I've run the testcd command and it says it's ok. when the x server quits what comes up on screen is something like this

Everything looks OK.
Processor 0 is Intel(R) Pentium(R) 4 CPU 1.70GHz 1694MHz, 256 KB Cache
/etc/init.d/apmd: line 15: /usr/bin/apm_available: Input/output error
APM Bios found, power management functions enabled.
PCMCIA found, starting cardmgr.
cardmgr[89]: starting, version 3.2.5
USB found, managed by hotplug: (Re-)scanning USB devices... sync:[001 001 ] Done.
Firewire found, managed by hotplug: (Re-)scanning firewire devices... Done.
Autoconfiguring devices... Done
Mouse is Generic PS/2 Wheel Mouse at /dev/psaux
Soundcard: Intel Corporation|82440MX AC97 Audio Controller driver=i810_audio
fread magic: Input/output error
AGP bridge detected.
Video is ATI|Radeon Mobility M7 LW [Radeon Mobility 7500], using XFree86(radeon) Srever
Monitor is Genreic Monitor, H:28.0-96.0kHz, V:50.0-75.0Hz
Using modes "1024x768" "800x600" "640x480"
Scanning for Harddisk partitions and creating /etc/fstab... Done
Network device eth0 detected, DHCP broadcasting for IP. (Backgrounding)
Automounter started for: floppy cdrom.
INIT: Entering runlevel: 5
Executing /etc/init.d/xsession start:

Starting single X-Window session for user knoppix.
Please stand by a few seconds while the optimal configuration is being determined.

After this session terminates, the system will automatically shut down.

Starting X11...


X-Window session termianted with errors.
Please check and retry '/etc/init.d/xsession start'.


About what you suggested that I should do, I don't know how I'm supposed to do it :-s I wrote those commands after the X server quitted but I got this:

root@tty1[/]# /var/log/XFree86.0.log
bash: /var/log/XFree86.0.log: Permission denied

Am I doing it the wrong way???
Thank you for the help.