I haven't read this entire thread, but I've read enough of it to know you guys will probably find my experience interesting.
I'm running an AMD Phenom II X2 555 BE processor (just like most of you) on a Gigabyte GMA-880-UD2h Revision 2.0 board. This is my second GMA-880-UD2H Rev 2.0 board. On the first board, I was able to unlock all 4 cores on my 555 BE processor, stable, no problems. The first board however, after about 4 months, ended up with a bad DIMM slot. I RMA'd it to Gigabyte and after the second repair attempt, they just sent me a new board altogether. EXACTLY the same model number and revision number, but a new board because the serial # was different. Since I've gotten the new board, my 555BE will NOT unlock whatsoever. The additional cores don't even appear in the BIOS when I try to use Core Unlocker. We're talking the BIOS only "sees" 2 cores.
This is quite annoying for me. I can't fathom why core unlocker would work on one board and then NOT work on EXACTLY the same board (other than the serial#)!?
Something fishy is going on here.