BFG 8800GTS overclocking problem

I have a BFG 8800GTS 320mb card in my machine and it seems to run ok. The problem I am having is with the overclock facility. The Card comes with a programme called XpertVision, which allows you to increase the Core Clock and the Memory Clock, there is a colour-coded dial for each, which you can increase. The dial starts off with a green section then changes to yellow then orange and finally a red section. Obviously the darker the colour the higher the settings. My problem is that if I increase the dial beyond the green setting the thing freezes when running 3dMark and I have to re-start the comp. I would have thought that if they give you an increase dial you should be able to take it out of the green section, even if only by a few mhz or what’s the point in giving you the option in the first place! Any ideas anyone, all advice gratefully received.

Comp: Asus P5N32-SLI SE Deluxe Motherboard, Intel Core 2 Duo E6700 2.66mhz running at 3.2mhz stable, BFG 8800GTS 320mb video, HP 19" Widescreen Monitor, 250GB Diamond Maxtor HD with 8MB Cache, 2024Mb 667mhz Ram, XBlade Case, Arctic Cooler 7 Pro, Creative XFi Sound Card, 18X DVD Re-Writer.

Rivatuner v2.03 is very good

Thanks for the advice, will go and look into Riva Tuna and see what happens, am running XP Home not Vista by the way.

Hi spuddyt (nearly spelt it right)
No reason really i guess just being polite and not taking the credit for someone else's knowledge.
Mactronix