I'm having the exact same problem! My system is:
Gigabyte P55A-UD4 rev.2.0
Core i5 760
MSI N460 GTX Cyclone 1GD5/OC
Kingston HyperX DDR3 Genesis (2x2GB)
WD6402aaex black caviar 640GB
trying to run windows 7 ultimate x64
At first I thought it was an HD related issue (because of the strange click noise) but it turns out the disk was fine. I ran the wd diagnostics test and i even had the disk returned to the shop were i got it from so they would check it as well. I also put a diffenent HD on and still the same problem.
PSU seems alright as well, tested it with a multimeter and all the readings were within the 5% margin.
After reseting the bios I still have the same problem.
Did you find the solution to this Jure or anybody else?