Ok cool . . . obviously one hour of Prime95 "blend" isn't total proof that the vCore is enough to keep that Intel® Core™2 Quad Q6600 100% stable @ 3.0GHz but its good enough for the moment! 
Theres two things to do which I think will drops the temps a bit more, the first is obviously dial down the vCore a bit more . . . if you go too low though the system will fail to boot windows or indeed reboot the system as soon as you load Prime95 . . .
The second thing is to go back into BIOS to this page again and change
CPU PLL Voltage from [Auto] to [Minimum/1.500v?]
If the board is giving the chip too much CPU PLL under [Auto] setting that will indeed be pushing the load temps up so its worth a try . . . if [1.500v] is too low the same thing will happen as when you UnderVolt the vCore too much (Failed load of Windows/Reboot Under Prime95 stress) . . .
In your shoes right now I would first whack CPU PLL down and run a quick test just to see if it lowers the temps and if indeed the system remains stable . . . If the temps don't drop further from that then I guess you may as well put CPU PLL back on [Auto] and see how much further you can reduce the vCore!

Theres two things to do which I think will drops the temps a bit more, the first is obviously dial down the vCore a bit more . . . if you go too low though the system will fail to boot windows or indeed reboot the system as soon as you load Prime95 . . .
The second thing is to go back into BIOS to this page again and change
CPU PLL Voltage from [Auto] to [Minimum/1.500v?]
If the board is giving the chip too much CPU PLL under [Auto] setting that will indeed be pushing the load temps up so its worth a try . . . if [1.500v] is too low the same thing will happen as when you UnderVolt the vCore too much (Failed load of Windows/Reboot Under Prime95 stress) . . .
In your shoes right now I would first whack CPU PLL down and run a quick test just to see if it lowers the temps and if indeed the system remains stable . . . If the temps don't drop further from that then I guess you may as well put CPU PLL back on [Auto] and see how much further you can reduce the vCore!
