i had a temp problem with my waterblock as well. I got the swiftech h20 220 ultra kit and i pulled off the mobo and seated the waterblocked and looked at it from 360 degrees to make sure the copper plate was actually in full contact with the processor.

I then applied thermal grease, and seated the waterblock again and securely mounted it to the mobo before mounting the mobo back into the case.

Before, i was seeing 80*C with water cooling which was ridiculous. I pulled everything off, cleaned the old thermal grease, did the aforementioned procedure, and now i'm running a cool 40*C on a 9x400 OC profile.

While under prime95 or everest, temps will go up to mid 60's to low 70's while at 100% load.

hope that helps some people