No wakeup after hybrid sleep (black screen)

I found a solution/workaround that works for me after some searching: disabling the USB 3.0 controller in BIOS (it's a 3rd party NEC/Renesas one, Gigabyte P55 mobo).
Now hybrid sleep resumes properly even after a power outage.

Interestingly enough, my USB 2.0 flash drive still works when connected to it, however my USB 3.0 HDD doesn't. Oh well, better than nothing.



EDIT: I spoke too soon.

Just as I thought it would finally work ok, another problem started happening, not when the power goes out but at normal sleep resume.
It seems like some components (or only the video card) don't resume, unless I press reset after trying to wake the PC.
I know it sounds weird, but others have this problem too (example).
I give up. But in case there's a solution I'll try it. (Already tried reinstalling the drivers etc., no help.)