> but my problem is that periodicly, the machine will just freeze while in 
> xwindows, to the point where my only option is to hit the reset button 
> (telnet in does not work, the machine dies)
> I get no kernel errors, no nothing.

Are you *sure* you get no kernel errors?  This precisely describes what
happens if your kernel panics and crashes to ddb; I've seen a lot of panics
recently, a bunch apparently caused by something overrunning malloced
storage and driving malloc() mad.