Thx for your answer simonsays,
I checked out the link you postet, so I find out that the memory on my card is L shaped.
So it should be 256bit
The other thing I've found, I have a golden cooler, that's the only difference...
So, if I install the Omega driver with the normal options, the same thing happend...
So, I believe I had to live with that in fact... holy crap
What do you think?