I'm sorry if I've skipped pass someone already saying this but why not just press Alt + Tab and then go to Task manager. Right click on the game being played and set the affinity to one core?. I've only had issues with the GodFather (FPS limiter is set to 30 and X2 pushed it to 45 which made it jumpy). And NHL06, would freeze about 2 times a second till I set the affinity to one CPU.
Every other game has been fine. I've used it for months without the dual core optimizer and only put it in a few days ago when I installed Company of Heroes. No change though.
I don't see how you didn't get a boost by going x850 to x1900 lol. I went from 9800pro to X800XT PE(AGP) to 7600GT OC (PCI-X) X1900XT and I noticed a big change each move.
Have you still got the same PC now?.
Every other game has been fine. I've used it for months without the dual core optimizer and only put it in a few days ago when I installed Company of Heroes. No change though.
I don't see how you didn't get a boost by going x850 to x1900 lol. I went from 9800pro to X800XT PE(AGP) to 7600GT OC (PCI-X) X1900XT and I noticed a big change each move.
Have you still got the same PC now?.

My bro purchased the cooler because I told him so after reading reviews (mostly testing with single core) + taking he's budget into account, felt guilty afterwards as he couldn’t return product so gave him my Evo120. So to answer your question – I’m talking from my personal experience with the product.
Yes we may have got a duff one or just bad luck and since un-returnable; bro is not willing to shell out & try again which understandable.