George wrote:
[...]

Good thought, but that's not a problem.  Comp gets cleaned once a month reguarly, since it's in a business environment.  Uninstalled SETIQueue (which, BTW, I notice the SQ homepage is gone) but still having problems with SETI hanging.

That 'business environment' means nothing for clean computers.

You may well have the outside of the case nice and clean and shiny. The inside may well be full of thermally insulating dust, with a fan choked to a feeble slow rotation, and everything running nicely hot.

If the insides are clean and the fans are working, then next try remounting the CPU heatsink with some fresh thermal grease (clean off the old stuff first). If still not working, then you've likely got some capacitors on their way out on the motherboard or in the PSUs.

Try memtest86 to check out the RAM, and the GIMPS torture test to check out the CPU & RAM.

Silicon runs better the cooler it is.

Good luck,
Martin