etch in amd64: system freezes

[Marcelo Chiapparini <chiappa@uerj.br>]

Dear list,

I have installed etch in a new AMD64 machine. My problem is the
following: after a very little activity in the Gnome desktop, the system
freezes (even an open window terminal freezes)  and only a hard reboot
bring the system back. 
If during the boot I interrupt the window manager with ctrl+alt+f11 and
switch to a terminal, with alt+f1 for example, the system works
perfectly. The problem seem to be with the graphical interface. 

I ran memtest86+, and everything is ok, no error was reported. My system
is the following:

CPU: Athlon64 2043 MHz
Mem: 1024 Mb
Chipset: VIA K8T800 pro (Abit AV8 motherboarad)
RAM: 204 MHz (DDR408) / CAS: 3-3-3-8 /DDR-1 (128 bits)
Video card: ATI Radeon Mobility 9200 (AGP)

I googled the internet and looked the debian arquives too (debian-user
and debian-amd64), but I didn't find any clue. I will appreciate very
much any help.

Thanks in advance

Marcelo


-- 
Marcelo Chiapparini
DFT-IF/UERJ
chiappa@uerj.br