Thank you very much for your replies!
I've got corsair memory and very satisfied with its performance. Within less than half an hour i succesffully set them to 1100mhz and cpu @3.9ghz. The system was stable for 7 hours and then i needed to go to work. I want to play more with advanced timings- now they are all on auto and will stress test the system at weekend for 15-17 hours to be sure everything ok.
If you want you can check my pc's video on you tube - http://www.youtube.com/watch?v=zLyMq4mkPt0