problem with video display in X

[Long Wind]

i have just installed Debian 6
it has problem with my video card
i have to set to 15 bit with /etc/X11/xorg.conf
if i use 16 bit or 32 bit, the monitor shows incorrectly
and i have to press power button to shutdown

I attach /var/log/Xorg.0.log

(now I go to sleep. (I will replay later, Thanks!))

Xorg.0.log
Description: Binary data