OCing q9300 on EP45-UD3P

Hey, I need some help ocing my q9300 on a Gigabyte ep45-ud3p mobo. I can overclock it to 3.0 ghz no problem, but then when I try to overclock to 3.2 ghz I have issues with system stability. The system will restart at random times. I ran prime95, and it will run for about 6 hrs or so, but then one of the workers will fail. I haven't changed the cpu voltage settings yet - not really sure what the added options with a quad core mean. I'm also not sure what people would recommend for the vcore. At auto it reads around 1.2V +/- .016 using cpuz. The bios says it's at 1.1625, so there's some error.

My cpu host frequency is 427, with a 7.5 multi, putting my cpu at 3.2ghz. I don't think my memory is the issue - it passes memtest fine. It's running at 1068 at stock timings - 5 5 5 15.

Here are my system specs:

Coolermaster 690
Corsair CMPSU-650TX 650W
Intel q9300
Gigabyte EP45-UD3P
OCZ Reaper HPC 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066
EVGA 512-P3-N879-AR GeForce 9800 GTX+ 512MB 256-bit GDDR3
XIGMATEK HDT-S1283 120mm Rifle CPU Cooler

Try putting in some more volts. You should be ok until atleast 1.3v vcore. You might also have to adjust reference voltages for your quad core.

What exactly does the cpu reference actually do?