Catalyst and HD6670 OC Problem

Hello all,

I have the following specs:

Core i5 2400
4gb Corsair Value select 1333
Windows 7 32 bit ultimate

Graphic card: Sapphire HD6670 with Catalyst 12.6


Issue: When I use AMD overdrive through catalyst and push the gpu clock beyond 800 MHz (900 max), the driver crashes and recovers (message: "AMD driver crashed and has successfully recovered")

Everything works fine till 800 MHz (the base clock for the gpu)

I have a 280 W psu which probably is undersized for my setup but everything works just fine with all components at their default settings.

I went here
http://support.amd.com/us/kbarticles/Pages/737-27116Rad...

and it lists PSU and OC'ing(advises against it) as possible reasons

why is there and OC'ing option in overdrive then??