I'm booting Knoppix from CD, and whatever I do I get a resolution that is so low the desktop's unusable. The problem seems to be when X11 wants to start. I get the desktop, but also the message [drm: drm_init] *Error* Cannot initialize the agpgart module.
I've tried many combinations of the hints and tips given in this forum without success. Hardware info: Monitor is Samsung SyncMaster 959NF, and it reports to be able to do 30-110kHz horizontal and 50-160Hz vertical. Recommended resolution according to Samsung is 1600*1200 at 87 Hz. For 1024*768 132 Hz seems recommended. The video controller is reported as Intel 82865G Integrated graphics device and XFree selects the i810 flavour unless I force it to do something else.

Output from lspci -v :
0000:00:00.0 Host bridge: Intel Corp. 82865G/PE/P DRAM Controller/Host-Hub Interface (rev 02)
Subsystem: Dell: Unknown device 0151
Flags: bus master, fast devsel, latency 0
Memory at f0000000 (32-bit, prefetchable) [size=128M]
Capabilities: [e4] #09 [0106]

0000:00:02.0 VGA compatible controller: Intel Corp. 82865G Integrated Graphics Device (rev 02) (prog-if 00 [VGA])
Subsystem: Dell: Unknown device 0151
Flags: fast devsel, IRQ 16
Memory at e8000000 (32-bit, prefetchable) [size=128M]
Memory at feb80000 (32-bit, non-prefetchable) [size=512K]
I/O ports at ed98 [size=8]
Capabilities: [d0] Power Management version 1

0000:00:1d.0 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI #1 (rev 02) (prog-if 00 [UHCI])
Subsystem: Dell: Unknown device 0151
Flags: bus master, medium devsel, latency 0, IRQ 16
I/O ports at ff80 [size=32]

0000:00:1d.1 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI #2 (rev 02) (prog-if 00 [UHCI])
Subsystem: Dell: Unknown device 0151
Flags: bus master, medium devsel, latency 0, IRQ 19
I/O ports at ff60 [size=32]

0000:00:1d.2 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI #3 (rev 02) (prog-if 00 [UHCI])
Subsystem: Dell: Unknown device 0151
Flags: bus master, medium devsel, latency 0, IRQ 18
I/O ports at ff40 [size=32]

0000:00:1d.3 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB UHCI #4 (rev 02) (prog-if 00 [UHCI])
Subsystem: Dell: Unknown device 0151
Flags: bus master, medium devsel, latency 0, IRQ 16
I/O ports at ff20 [size=32]

0000:00:1d.7 USB Controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) USB2 EHCI Controller (rev 02) (prog-if 20 [EHCI])
Subsystem: Dell: Unknown device 0151
Flags: bus master, medium devsel, latency 0, IRQ 23
Memory at ffa80800 (32-bit, non-prefetchable) [size=1K]
Capabilities: [50] Power Management version 2
Capabilities: [58] #0a [20a0]

0000:00:1e.0 PCI bridge: Intel Corp. 82801 PCI Bridge (rev c2) (prog-if 00 [Normal decode])
Flags: bus master, fast devsel, latency 0
Bus: primary=00, secondary=01, subordinate=01, sec-latency=32
I/O behind bridge: 0000d000-0000dfff
Memory behind bridge: fea00000-feafffff

0000:00:1f.0 ISA bridge: Intel Corp. 82801EB/ER (ICH5/ICH5R) LPC Bridge (rev 02)
Flags: bus master, medium devsel, latency 0

0000:00:1f.1 IDE interface: Intel Corp. 82801EB/ER (ICH5/ICH5R) Ultra ATA 100 Storage Controller (rev 02) (prog-if 8a [Master SecP PriP])
Subsystem: Dell: Unknown device 0151
Flags: bus master, medium devsel, latency 0, IRQ 18
I/O ports at <ignored>
I/O ports at <ignored>
I/O ports at <ignored>
I/O ports at <ignored>
I/O ports at ffa0 [size=16]
Memory at feb7fc00 (32-bit, non-prefetchable) [size=1K]

0000:00:1f.2 IDE interface: Intel Corp. 82801EB (ICH5) Serial ATA 150 Storage Controller (rev 02) (prog-if 8f [Master SecP SecO PriP PriO])
Subsystem: Dell: Unknown device 0151
Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 18
I/O ports at fe00 [size=8]
I/O ports at fe10 [size=4]
I/O ports at fe20 [size=8]
I/O ports at fe30 [size=4]
I/O ports at fea0 [size=16]

0000:00:1f.3 SMBus: Intel Corp. 82801EB/ER (ICH5/ICH5R) SMBus Controller (rev 02)
Subsystem: Dell: Unknown device 0151
Flags: medium devsel, IRQ 17
I/O ports at eda0 [size=32]

0000:00:1f.5 Multimedia audio controller: Intel Corp. 82801EB/ER (ICH5/ICH5R) AC'97 Audio Controller (rev 02)
Subsystem: Dell: Unknown device 0151
Flags: bus master, medium devsel, latency 0, IRQ 17
I/O ports at ee00 [size=256]
I/O ports at edc0 [size=64]
Memory at feb7fa00 (32-bit, non-prefetchable) [size=512]
Memory at feb7f900 (32-bit, non-prefetchable) [size=256]
Capabilities: [50] Power Management version 2

0000:01:0c.0 Ethernet controller: Intel Corp. 82540EM Gigabit Ethernet Controller (rev 02)
Subsystem: Dell: Unknown device 0151
Flags: bus master, 66MHz, medium devsel, latency 64, IRQ 18
Memory at feae0000 (32-bit, non-prefetchable) [size=128K]
I/O ports at df40 [size=64]
Capabilities: [dc] Power Management version 2
Capabilities: [e4] PCI-X non-bridge device.
Capabilities: [f0] Message Signalled Interrupts: 64bit+ Queue=0/0 Enable-

----------------------------------------------------------------------------
Output from lsmod:
Module Size Used by Not tainted
i830 69536 13
agpgart 42724 11 (autoclean)
autofs4 8756 1 (autoclean)
af_packet 13544 0 (autoclean)
nls_iso8859-1 2844 0 (autoclean)
nls_cp437 4348 0 (autoclean)
i810_audio 25048 1
ac97_codec 11916 0 [i810_audio]
soundcore 3428 2 [i810_audio]
e1000 62696 1
hw_random 2700 0 (unused)
serial 52100 0 (autoclean)
mousedev 3832 0
hid 22564 0 (unused)
input 3168 0 [mousedev hid]
pcmcia_core 39840 0
thermal 6724 0 (unused)
processor 9008 0 [thermal]
fan 1600 0 (unused)
button 2700 0 (unused)
battery 5952 0
ac 1824 0
rtc 7036 0 (autoclean)
cloop 8740 2
ieee1394 183076 0
usb-storage 61760 0 (unused)
usb-uhci 21644 0 (unused)
usbcore 57600 1 [hid usb-storage usb-uhci]
ataraid 6180 0
ide-scsi 8816 1
-----------------------------------------------------------------------------------
XF86Config-4:
Section "ServerLayout"
Identifier "XFree86 Configured"
Screen 0 "Screen0" 0 0
InputDevice "Keyboard0" "CoreKeyboard"
# PS/2 Mouse not detected
# Serial Mouse not detected
InputDevice "USB Mouse" "CorePointer"
EndSection

Section "ServerFlags"
Option "AllowMouseOpenFail" "true"

EndSection

Section "Files"
RgbPath "/usr/X11R6/lib/X11/rgb"
ModulePath "/usr/X11R6/lib/modules"
FontPath "/usr/X11R6/lib/X11/fonts/misc:unscaled"
FontPath "/usr/X11R6/lib/X11/fonts/misc"
FontPath "/usr/X11R6/lib/X11/fonts/75dpi:unscaled"
FontPath "/usr/X11R6/lib/X11/fonts/75dpi"
FontPath "/usr/X11R6/lib/X11/fonts/100dpi:unscaled"
FontPath "/usr/X11R6/lib/X11/fonts/100dpi"
FontPath "/usr/X11R6/lib/X11/fonts/Speedo"
FontPath "/usr/X11R6/lib/X11/fonts/PEX"
# Additional fonts: Locale, Gimp, TTF...
FontPath "/usr/X11R6/lib/X11/fonts/cyrillic"
# FontPath "/usr/X11R6/lib/X11/fonts/latin2/75dpi"
# FontPath "/usr/X11R6/lib/X11/fonts/latin2/100dpi"
# True type and type1 fonts are also handled via xftlib, see /etc/X11/XftConfig!
FontPath "/usr/X11R6/lib/X11/fonts/Type1"
FontPath "/usr/share/fonts/ttf/western"
FontPath "/usr/share/fonts/ttf/decoratives"
FontPath "/usr/share/fonts/truetype"
FontPath "/usr/share/fonts/truetype/openoffice"
FontPath "/usr/share/fonts/truetype/ttf-bitstream-vera"
FontPath "/usr/share/fonts/latex-ttf-fonts"
FontPath "/usr/X11R6/lib/X11/fonts/defoma/CID"
FontPath "/usr/X11R6/lib/X11/fonts/defoma/TrueType"
EndSection

Section "Module"
Load "ddc" # ddc probing of monitor
Load "GLcore"
Load "dbe"
Load "dri"
Load "extmod"
Load "glx"
Load "bitmap" # bitmap-fonts
Load "speedo"
Load "type1"
Load "freetype"
Load "record"
EndSection

Section "InputDevice"
Identifier "Keyboard0"
Driver "keyboard"
Option "CoreKeyboard"
Option "XkbRules" "xfree86"
Option "XkbModel" "pc105"
Option "XkbLayout" "us"

EndSection

Section "InputDevice"
Identifier "Serial Mouse"
Driver "mouse"
Option "Protocol" "Microsoft"
Option "Device" "/dev/ttyS0"
Option "Emulate3Buttons" "true"
Option "Emulate3Timeout" "70"
Option "SendCoreEvents" "true"
EndSection

Section "InputDevice"
Identifier "PS/2 Mouse"
Driver "mouse"
Option "Protocol" "auto"
Option "ZAxisMapping" "4 5"
Option "Device" "/dev/psaux"
Option "Emulate3Buttons" "true"
Option "Emulate3Timeout" "70"
Option "SendCoreEvents" "true"
EndSection

Section "InputDevice"
Identifier "USB Mouse"
Driver "mouse"
Option "Device" "/dev/input/mice"
Option "SendCoreEvents" "true"
Option "Protocol" "IMPS/2"
Option "ZAxisMapping" "4 5"
Option "Buttons" "5"
EndSection

# Auto-generated by KNOPPIX mkxf86config

Section "Monitor"
Identifier "Monitor0"
Option "DPMS" "true"
VendorName "Samsung"
ModelName "SyncMaster 900p"
HorizSync 30-110# DDC-probed
VertRefresh 50-160# DDC-probed
# These are the DDC-probed settings reported by your monitor.
# 1600x1200, 85.0Hz; hfreq=106.25, vfreq=85.00
ModeLine "1600x1200" 229.50 1600 1664 1856 2160 1200 1201 1204 1250 +hsync +vsync
# 1600x1200, 75.0Hz; hfreq=93.75, vfreq=75.00
ModeLine "1600x1200" 202.50 1600 1664 1856 2160 1200 1201 1204 1250 +hsync +vsync
# 1280x1024, 85.0Hz; hfreq=91.15, vfreq=85.02
ModeLine "1280x1024" 157.50 1280 1344 1504 1728 1024 1025 1028 1072 +hsync +vsync
# 1280x1024, 75.0Hz; hfreq=79.98, vfreq=75.03
ModeLine "1280x1024" 135.00 1280 1296 1440 1688 1024 1025 1028 1066 +hsync +vsync
# 1024x768, 85.0Hz; hfreq=68.68, vfreq=85.00
ModeLine "1024x768" 94.50 1024 1072 1168 1376 768 769 772 808 +hsync +vsync
# 1024x768, 75.0Hz; hfreq=60.02, vfreq=75.03
ModeLine "1024x768" 78.75 1024 1040 1136 1312 768 769 772 800 +hsync +vsync
# 1024x768, 70.0Hz; hfreq=56.48, vfreq=70.07
ModeLine "1024x768" 75.00 1024 1048 1184 1328 768 771 777 806 -hsync -vsync
# 1024x768, 60.0Hz; hfreq=48.36, vfreq=60.00
ModeLine "1024x768" 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync
# 800x600, 85.0Hz; hfreq=53.67, vfreq=85.06
ModeLine "800x600" 56.25 800 832 896 1048 600 601 604 631 +hsync +vsync
# 800x600, 75.0Hz; hfreq=46.88, vfreq=75.00
ModeLine "800x600" 49.50 800 816 896 1056 600 601 604 625 +hsync +vsync
# 800x600, 72.0Hz; hfreq=48.08, vfreq=72.19
ModeLine "800x600" 50.00 800 856 976 1040 600 637 643 666 +hsync +vsync
# 800x600, 60.0Hz; hfreq=37.88, vfreq=60.32
ModeLine "800x600" 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync
# 800x600, 56.0Hz; hfreq=35.16, vfreq=56.25
ModeLine "800x600" 36.00 800 824 896 1024 600 601 603 625 +hsync +vsync
# 640x480, 75.0Hz; hfreq=37.50, vfreq=75.00
ModeLine "640x480" 31.50 640 656 720 840 480 481 484 500 -hsync -vsync
# 640x480, 72.0Hz; hfreq=37.86, vfreq=72.81
ModeLine "640x480" 31.50 640 656 696 816 480 481 484 504 -hsync -vsync
# 640x480, 60.0Hz; hfreq=31.47, vfreq=59.94
ModeLine "640x480" 25.17 640 648 744 784 480 482 484 509 -hsync -vsync
# Extended modelines with GTF timings
# 640x480 @ 100.00 Hz (GTF) hsync: 50.90 kHz; pclk: 43.16 MHz
ModeLine "640x480" 43.16 640 680 744 848 480 481 484 509 -HSync +Vsync
# 768x576 @ 60.00 Hz (GTF) hsync: 35.82 kHz; pclk: 34.96 MHz
ModeLine "768x576" 34.96 768 792 872 976 576 577 580 597 -HSync +Vsync
# 768x576 @ 72.00 Hz (GTF) hsync: 43.27 kHz; pclk: 42.93 MHz
ModeLine "768x576" 42.93 768 800 880 992 576 577 580 601 -HSync +Vsync
# 768x576 @ 75.00 Hz (GTF) hsync: 45.15 kHz; pclk: 45.51 MHz
ModeLine "768x576" 45.51 768 808 888 1008 576 577 580 602 -HSync +Vsync
# 768x576 @ 85.00 Hz (GTF) hsync: 51.42 kHz; pclk: 51.84 MHz
ModeLine "768x576" 51.84 768 808 888 1008 576 577 580 605 -HSync +Vsync
# 768x576 @ 100.00 Hz (GTF) hsync: 61.10 kHz; pclk: 62.57 MHz
ModeLine "768x576" 62.57 768 816 896 1024 576 577 580 611 -HSync +Vsync
# 800x600 @ 100.00 Hz (GTF) hsync: 63.60 kHz; pclk: 68.18 MHz
ModeLine "800x600" 68.18 800 848 936 1072 600 601 604 636 -HSync +Vsync
# 1024x768 @ 100.00 Hz (GTF) hsync: 81.40 kHz; pclk: 113.31 MHz
ModeLine "1024x768" 113.31 1024 1096 1208 1392 768 769 772 814 -HSync +Vsync
# 1152x864 @ 60.00 Hz (GTF) hsync: 53.70 kHz; pclk: 81.62 MHz
ModeLine "1152x864" 81.62 1152 1216 1336 1520 864 865 868 895 -HSync +Vsync
# 1152x864 @ 85.00 Hz (GTF) hsync: 77.10 kHz; pclk: 119.65 MHz
ModeLine "1152x864" 119.65 1152 1224 1352 1552 864 865 868 907 -HSync +Vsync
# 1152x864 @ 100.00 Hz (GTF) hsync: 91.50 kHz; pclk: 143.47 MHz
ModeLine "1152x864" 143.47 1152 1232 1360 1568 864 865 868 915 -HSync +Vsync
# 1280x960 @ 72.00 Hz (GTF) hsync: 72.07 kHz; pclk: 124.54 MHz
ModeLine "1280x960" 124.54 1280 1368 1504 1728 960 961 964 1001 -HSync +Vsync
# 1280x960 @ 75.00 Hz (GTF) hsync: 75.15 kHz; pclk: 129.86 MHz
ModeLine "1280x960" 129.86 1280 1368 1504 1728 960 961 964 1002 -HSync +Vsync
# 1280x960 @ 100.00 Hz (GTF) hsync: 101.70 kHz; pclk: 178.99 MHz
ModeLine "1280x960" 178.99 1280 1376 1520 1760 960 961 964 1017 -HSync +Vsync
# 1280x1024 @ 100.00 Hz (GTF) hsync: 108.50 kHz; pclk: 190.96 MHz
ModeLine "1280x1024" 190.96 1280 1376 1520 1760 1024 1025 1028 1085 -HSync +Vsync
# 1400x1050 @ 60.00 Hz (GTF) hsync: 65.22 kHz; pclk: 122.61 MHz
ModeLine "1400x1050" 122.61 1400 1488 1640 1880 1050 1051 1054 1087 -HSync +Vsync
# 1400x1050 @ 72.00 Hz (GTF) hsync: 78.77 kHz; pclk: 149.34 MHz
ModeLine "1400x1050" 149.34 1400 1496 1648 1896 1050 1051 1054 1094 -HSync +Vsync
# 1400x1050 @ 75.00 Hz (GTF) hsync: 82.20 kHz; pclk: 155.85 MHz
ModeLine "1400x1050" 155.85 1400 1496 1648 1896 1050 1051 1054 1096 -HSync +Vsync
# 1400x1050 @ 85.00 Hz (GTF) hsync: 93.76 kHz; pclk: 179.26 MHz
ModeLine "1400x1050" 179.26 1400 1504 1656 1912 1050 1051 1054 1103 -HSync +Vsync
# 1400x1050 @ 100.00 Hz (GTF) hsync: 111.20 kHz; pclk: 214.39 MHz
ModeLine "1400x1050" 214.39 1400 1512 1664 1928 1050 1051 1054 1112 -HSync +Vsync
# 1600x1200 @ 100.00 Hz (GTF) hsync: 127.10 kHz; pclk: 280.64 MHz
ModeLine "1600x1200" 280.64 1600 1728 1904 2208 1200 1201 1204 1271 -HSync +Vsync
ModeLine "1280x1024/100Hz" 181.75 1280 1312 1440 1696 1024 1031 1046 1072 -HSync -VSync
EndSection

Section "Device"
### Available Driver options are:-
# sw_cursor is needed for some ati and radeon cards
#Option "sw_cursor"
#Option "hw_cursor"
#Option "NoAccel"
#Option "ShowCache"
#Option "ShadowFB"
#Option "UseFBDev"
#Option "Rotate"
Identifier "Card0"
# The following line is auto-generated by KNOPPIX mkxf86config
Driver "vga"
VendorName "Generic"
BoardName "vga"
# BusID "PCI:1:0:0"
EndSection

Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
DefaultColorDepth 16
SubSection "Display"
Depth 1
Modes "1280x1024/100Hz" "640x480"
Virtual 0 0
EndSubSection
SubSection "Display"
Depth 4
Modes "1280x1024/100Hz" "640x480"
Virtual 0 0
EndSubSection
SubSection "Display"
Depth 8
Modes "1280x1024/100Hz" "640x480"
Virtual 0 0
EndSubSection
SubSection "Display"
Depth 15
Modes "1280x1024/100Hz" "640x480"
Virtual 0 0
EndSubSection
SubSection "Display"
Depth 16
Modes "1280x1024/100Hz" "640x480"
Virtual 0 0
EndSubSection
SubSection "Display"
Depth 24
Modes "1280x1024/100Hz" "640x480"
Virtual 0 0
EndSubSection
SubSection "Display"
Depth 32
Modes "1280x1024/100Hz" "640x480"
Virtual 0 0
EndSubSection
EndSection

Section "DRI"
Mode 0666
EndSection

Section "InputDevice"

Identifier "Mouse"

Option "Protocol" ""
Option "Device" "/dev/mouse"
Driver "mouse"
Option "Emulate3Buttons"
Option "ZAxisMapping" "4 5"
EndSection
-----------------------------------------------------------------------------
Grateful for help.