ubuntu freezes for no reason....

[Charles Malespin]

Hi all, I am very new to linux and ubuntu and so far I only have one
major gripe about it...  Every once in a while everything freezes up and
I have to do a hard reboot to start up again.  I cant move anything or
do anything once it does it, and it does it randomly with no pattern.  I
was using FC3 briefly before this on the same computer(havent added or
changed anything) and it would freeze too, until I upgraded to the
2.6.11 kernel.  Then no more freezes.  I am running a dual boot with XP
on the other side, video card is the ATI X300.  Any ideas?  Thanks, 
Charles