My core voltage is set to 1.80. The lockups seem to occur at 1.85 also. The computer doesn't freeze while it's idle or anything.. It usually freezes when I'm running a large self extracting install file (e.g. the 50 meg BeOS file). The hdd and the processor are working harder than normal, and my +5 voltage usually drops to below 5 (4.9 or so, don't know if that matters).