After disabling ULPS 4 days ago, my 5970 + EK waterblock system is now rock-stable in 2D and 3D. I'm gaming non stop almost 12 hours a day, and didn't got a single BSOD, freeze or any other issue in games (I'm playing Dragon Age, Resident Evil 5, Batman AA, Torchlight).

I also did a couple of hours of Phtoshop CS4 and AVC-HD video editing without a single problem.

So it must be the way people are mounting the EK waterblock. Or a really strange driver problem. I don't know.

I had some problems the first 2 days. But now everything is working fine for me. Disabling ULPS and letting my computer working 24/24 solved all my problems.