Problems with sporadic freezes and high jitter

Does not help either
But I will try the software openGL libraries on 10.04.

Fingers crossed, that has helped in the past where lockups are related to openGL

Could it be a process or module that is interrupting?

Hard to think what could be interrupting that often.
Will do no harm to unload bluetooth, cron and anything else you are not using.

The first place I would normally look would be BIOS. There is obviously no fan control, but normally there will be power control, sleep etc which need disabling and possibly hyperthreading too with a lot of Intel single core stuff.

Lets see what happens with 10.04

regards