> my qube2 locks up at more or less random times.
...
> Most of the time the box locks up during large nfs file transfers but
> it also crashed while compiling stuff.

How often?  Can you reliably make it occur?  I've suffered 1 lockup
running 1.6 beta 4 during large NFS file transfers (10 to 12 50-60M
files in a row).  I've since upgraded to 1.6 release (used build.sh,
no lockups, nice and smooth), so far no lockups, haven't hammered it
quite as hard yet though.  Still I wasn't able to reliably reproduce
the crash, and the first time it happened I didn't have the console
monitored so I'm not sure what really happened.

-- 
Jamie Heilman                   http://audible.transient.net/~jamie/
"Most people wouldn't know music if it came up and bit them on the ass."
                                                        -Frank Zappa