You have no modlines in your monitor section for example my XF86Config-4 from a install of Bonzai linux a Debian derivative.
Code:
### BEGIN DEBCONF SECTION
# XF86Config-4 (XFree86 server configuration file) generated by dexconf, the
# Debian X Configuration tool, using values from the debconf database.
#
# Edit this file with caution, and see the XF86Config-4 manual page.
# (Type "man XF86Config-4" at the shell prompt.)
#
# If you want your changes to this file preserved by dexconf, only make changes
# before the "### BEGIN DEBCONF SECTION" line above, and/or after the
# "### END DEBCONF SECTION" line below.
#
# To change things within the debconf section, run the command:
#   dpkg-reconfigure xserver-xfree86
# as root.  Also see "How do I add custom sections to a dexconf-generated
# XF85Config or XF86Config-4 file?" in /usr/share/doc/xfree86-common/FAQ.gz.

Section "Files"
#       FontPath        "unix/:7100"                    # local font server
        # if the local font server has problems, we can fall back on these
#       FontPath        "/usr/lib/X11/fonts/Type1"
#       FontPath        "/usr/share/fonts/truetype/ttf-bitstream-vera"
        FontPath        "/usr/lib/X11/fonts/CID"
        FontPath        "/usr/lib/X11/fonts/Speedo"
        FontPath        "/usr/lib/X11/fonts/misc"
        FontPath        "/usr/lib/X11/fonts/cyrillic"
        FontPath        "/usr/lib/X11/fonts/75dpi"
        FontPath        "/usr/lib/X11/fonts/100dpi"
        FontPath        "/usr/share/fonts/truetype/ttf-bitstream-vera"
        FontPath        "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
        FontPath        "/usr/lib/X11/fonts/type1"
EndSection

Section "Module"
        Load    "GLcore"
        Load    "bitmap"
        Load    "dbe"
        Load    "ddc"
        Load    "dri"
        Load    "extmod"
        Load    "freetype"
        Load    "glx"
        Load    "int10"
        Load    "record"
        Load    "speedo"
        Load    "type1"
        Load    "vbe"
EndSection

Section "InputDevice"
        Identifier      "Generic Keyboard"
        Driver          "keyboard"
        Option          "CoreKeyboard"
        Option          "XkbRules"      "xfree86"
        Option          "XkbModel"      "pc101"
        Option          "XkbLayout"     "us"
EndSection

Section "InputDevice"
        Identifier      "Configured Mouse"
        Driver          "mouse"
        Option          "CorePointer"
        Option          "Device"                "/dev/psaux"
        Option          "Protocol"              "ImPS/2"
        Option          "Emulate3Buttons"       "true"
        Option          "ZAxisMapping"          "4 5"
EndSection

Section "InputDevice"
        Identifier      "Generic Mouse"
        Driver          "mouse"
        Option          "SendCoreEvents"        "true"
        Option          "Device"                "/dev/input/mice"
        Option          "Protocol"              "ImPS/2"
        Option          "Emulate3Buttons"       "true"
        Option          "ZAxisMapping"          "4 5"
EndSection

Section "Device"
        Identifier      "ATI Technologies, Inc. 3D Rage Pro AGP [264GT Pro GB]"
        Driver          "ati"
        Option          "UseFBDev"              "true"
EndSection

Section "Monitor"
        Identifier      "API:3645"
#       HorizSync       28-50
#       VertRefresh     43-75
        HorizSync    30-54# Warning: This may fry old Monitors
        VertRefresh 50-120
        Option          "DPMS"
vendorname "Acer Peripherals"
modelname "54e"
ModeLine "1024x768/65Hz" 65 1024 1032 1176 1344 768 771 777 806  -HSync -VSync
ModeLine "800x600/72Hz" 50 800 856 976 1040 600 637 643 666  +HSync +VSync


EndSection

Section "Screen"
        Identifier      "Default Screen"
        Device          "ATI Technologies, Inc. 3D Rage Pro AGP [264GT Pro GB]"
        Monitor         "API:3645"
        DefaultDepth    24
        SubSection "Display"
                Depth           1
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           4
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           8
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           15
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           16
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           24
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
EndSection

Section "ServerLayout"
        Identifier      "Default Layout"
        Screen          "Default Screen"
        InputDevice     "Generic Keyboard"
        InputDevice     "Configured Mouse"
        InputDevice     "Generic Mouse"
EndSection

Section "DRI"
        Mode    0666
EndSection

## END DEBCONF SECTION
As you can see they are similar except the monitor section and you have a couple extra modules being loaded. You should boot from the Knoppix CD and copy the modlines from the Knoppix config to your config file and you should be able to start the X server or maybe copy the whole file but comment out the fontpaths that will not be there, this of course after having backed up the original non-working file just in case you want to try with it again.