Debian Squeeze got frozen

[Hoang Le <linux.lehoang@gmail.com>]

Hi all,

I'm using Debian Squeeze with Gnome. Just 30mins ago, my desktop got
frozen. I don't know why. I must reset my PC by holding power button
to force shutting down. This happened several times before. I guess
Gnome is not working fine enough, but I have no evidences.

How can I know what happened to my system? I tried to look at system
logs with Log File Viewer in Gnome but haven't found out yet (I'm
don't know much about Linux system). It's find if it just happens to
me, I just don't feel safe to leave that bug uncovered.

Thank you,
Hoang