Think its all in the crash reports.

We've been doing stuff with chickens (nothing dirty) - and a little redstone clock to push eggs out of a dispenser. It feels like the server gets slower and slower and slower and eventually crashes.
The server machine has two of these in :
model name : Intel(R) Xeon(R) CPU X5365 @ 3.00GHz
and 32 Gb RAM.
Its not running anything else at the moment so there's no other load.
Let me know if you need an more info.