Wacky Radeon 8500 o/c problem

I just got a radeon 8500 and I am now trying to o/c. I have tried a coupl different programs and the same thing happens...if I change anything my screen goes crazy. Like 6 or 7 columns come up all varying in different colors. Whats going on???? Please help me...

please help me....I am desperate!!!

What kind of 8500 is it? Retail or LE? and what are you using to overclock?

Is that for a mHz or two or are you going from 275 to 310 or something?

like 1 or 2 mhz. It is retail....

Yeah, I am stumped.
What are the couple different progs you have used?

radeonator
r3d
radeon tweaker

Any ideas?

if you leave the core at stock speeds, can you overclock the ram without issues?

my vid card would not overclock the core at all.. I was stuck at 275.. but my ram would go to 290 just fine.. I ended up doing a hardware volt mod (no pencil) to my card also changing out the stock fan for a custom fan and ramsinks.. I now can get 297/300 stable with no artifacts.. However some people can go higher with a stock set up.. I just got a bummer card..

I use Powerstrip to do my overclocking..