Installed new F8 - looks stable, and even saw an improvement, PHC temp went from 58C to 37C, which is very pleasant surprise.
Although, I am still having issue with with PC not coming back from Sleep properly in windows, tried with optimized def. on F8.
Putting it to sleep, everything is fine - when waking on keyboard, it seems like its trying to but not enough power is provided to mobo, fans are kind of spinning up, little sequence counter is not coming on the motherboard, and it just shuts down. When manually powering back up - it tried to "kind of" come up again, and on the second try boots up.
I observed the same, right after the BIOS was flushed to the newer - reset the PC and it didn't come back up on the first try, rather tried to with slowly spinning fans, and booted up on second try.
If anyone is having the same issue let me know, since maybe its just my unlucky config. (This never happens on regular restart / power on/off)