IP35 shutdown problem

[funkydim]

Hi Guys
I have the following specs:
Intel Quad Core Q6600 with a Scythe Ninja Plus Rev B
ABIT/IP-35 S775 MOBO
Enermax 650w infinti PSU
4GB (2x2GB) Corsair TwinX XMS2
XFX Geforce 8800 Ultra

Ive had it since the start of the year and it works absolutely fine with one small problem that ive just been living with.

The computer will not shutdown. Ever. It just restarts everytime (via dual boot). Ive become used to just switching the power off at the mains when i shutdown, but this cause problems with dates and times and is just plain annoying.

Ive updated to the latest bios and read so many articles with similar kinds of problems, but most refer to the dual booting and nothing i do will work. I just want the damn thing to switch off when im done.

Any help you can offer would be great.

Cheers

[BUFF]

normally this is either caused by a "wake-on" setting or a PSU problem.