I am having troubles New cpu

[ckfantasy]

My first computer built by me I have had experience with older pentium system. Specs are

3200+ winchester
Neo2 Platinum MB
3200 ocz rev2
2 74 gig raptors
6800gt
nec 3500a dvd

I am having trouble overclocking. I want to acheive a stable 2.4 but everytime I set the settings in the cell menu and save, my computer restarts and says it is in safe mode and that I should reset my overclocking options.

I have my 6800 gt clocked at 384 1070

When I run doom3 the game comes to a crawl damn near in large areas and many enemies around
4xaa 8xaf resolution one better than 800x600 details all on

Also I ran Half- Life 2 and accidentilly set it at 1600x1200 and my monitor doesn't support that resolution so everytime I enter the game my screen is messed up and I can't change it back.

I have upgraded my bios and the nforce drivers also my vga to I really haven't played doom3 since I did that so maybe it's better now I guess I'll see.
I wanted to build a system not to far from the top and I just want it running optimum so any help anyone might be able to share would be highly appreciated.
Thanks

 

[klah]

I want to acheive a stable 2.4 but everytime I set the settings in the cell menu and save, my computer restarts and says it is in safe mode and that I should reset my overclocking options.

What settings are you reaching where this occurs? What do you have htt multiplier, memory divider, vcore, etc. at?