has anyone experienced a need to boost Vcore after a while?

strange, but a couple of days ago my computer became completely unstable after 2 months of running super stable....random restarts often, and a couple of restarts that would end up in non-reboots; had to turn PSU off, and start over.

I bumped Vcore from 1.28750 to 1.29325 and a little better but still rebooted. Then up to 1.3000v, and almost good but had two more reboots. Up to 1.3250 and now it is stable again! I didn't want to run that high of a Vcore, so I went back to FSB = 430 (3.89ghz), and put the Vcore down to 1.2835 and now it is running perfectly fine.

my board is a Asus P5Q-E, see my sig for more details