hoary freezes : how to trace and why ?

[Renaud Vernet]

Hi !

My system freezes sometimes, on my laptop.
This problem happens not everyday, but let's say... every week, although 
I use my computer ~12 hours a day.

So I have 2 questions :

- how to trace this ? I guess I have to look in the /var/log/something, 
but what kind of message should I look for ?

- it *looks like* it is a networking issue, because it happens when I am 
connected, or when I transfer a lot.

I have a dell inspiron 6000, with kernel 2.6.10 compiled by myself, b44 
ethernet driver.

Anybody could help me, please ?