ABIT AT8 Crossfire Motherboard
 

Later, out of coincidence I disconnected the CPU fan and the system shut down (Shutdown enable for CPU fan in ABIT EQ) and *poof* now system booted with the cleared CMOS. So every time the system hung at C1 after clearing CMOS I just had to disconnect the CPU fan, let the system shutdown and then everything worked normally.

Now knowing all the issues I set out to work with my BH5 memory: Set CAS2 - don't reboot until done with benchmarks. "Don't reboot" may sound easy but it's a pain for day to day use, and even more annoying when trying to find the maximum FSB which the board can at run without crashing.