I have experienced a few freezes running 2.0beta kernels.  A moment ago,
I was about to save an image from gimp and the system froze.  The X display
remained visible, but the mouse and keyboard were all dead (no caps lock
operation even).  I waited for some 15 minutes and the system didn't reboot
or recover.  All the time, I was able to ping the system from a remote
machine.

I have seen this before.  I thought it was a disk problem, replaced the
disk with a new one (different make as well), no help.  Sometimes the
system freezes for about 10 seconds and then comes back alive, sometimes
I have to push the reset button to get it going again.

This has been going on for months.  The system is usually stable, but every
now and then (one or twice a month) it freezes like this.  I think it happens
during heavy disk / memory load, but I'm not completely sure.

  -jm