P4B266....can't hardly OC

It's weird....I have run it for like 1 month at 130 FSB, nothing big. But, AS SOON as I hit 133 (2400) I get all kinds of boot errors from windows....files missing, corrupted files, all sorts of fun stuff. But, I go back to 130 and all is well again.

Right now I am at stock (100) due to some Folding issues.

Specs? PS? Mine was doing 2.4 with a 1.6a.

P4B266 (w/ integrated Audio, no Network)
Pentium 4 1.8a (C-1)
256MB DDR SDRAM (266mhz)
Radeon 7500 64MB AGP
Maxtor 60GB, Western Digital 80GB
Cheap 56K v.92 modem (Somewhat new, no changes since install)
Philips DVDRW228 (2.4X DVD+R/RW, 12X12X32X CDR/RW)
Asus CRW4816-A (48X16X48X )
Standard Floppy Drive
Either a 300 or 350 Watt PSU (can check if needed)

Windows 2000 (All updates)
Intel Application Accelerator
PC-Chillin Anti-Virus (came with mobo)

The key for me is Folding@Home. I don't recall ever having a problem OC'in before I started Folding. I had it at 140 FSB +/- for around 2 months with no problems. Now, if I take it to 110 FSB I get random restarts with no notice.