are you running the stock Intel cooler? If so check if it's thermal compound hasn't dried up. If that's the case, just buy some new and apply it. What you could also try is getting that Vengeance down to 1333Mhz. I have 8 gigs of it myself and I started experiencing some BSOD's after going to 1600Mhz, though that doesn't bother me, it's only like 2 times a week.