990FX Pro issues

[Eagle5]

Got a 990FX Professional for christmas and swapped it with the MSI 760GM-P35 that had been in my machine. Since then, I've been having a range of issues.

My Computer:
990FX fatality professional motherboard, BIOS v1.50
AMD Phenom II X4 955 Quad-Core processor, Stock Heatsink
G.SKILL DDR3 1333 RAM
Seagate Barracuda 500GB 7200RPM 16MB cache
Currently, CoolerMaster 1000W SilentPro (Modular, Single 12V Rail)
**Before this morning, Xpower 1080w Modular
Normally run with two XFX GeForce 9600 GSO's in SLI, has also been used with XFX Radeon HD 5570
Memorex SATA DVD/CD reader/writer
Zonet PCI wireless card

Issues:
-After the OEM logo screen, it fades to black and doesn't come back up until the windows log on screen (no "starting windows" screen)
-Recently, after logging in, the screen will fade to black and not come back up, but there's no "no signal" message from my monitor
-The power button (case and onboard) actually started the computer maybe 10% of the time
**I fixed this issue by replacing the Xpower 1080 in the machine with a CoolerMaster SilentPro 1000w, still here for potential reference purposes**
-USB devices have recently stopped working until the windows log on screen appears (Can't access BIOS anymore)
-Machine would power on by itself
-No bass from onboard sound (really the least of my concerns, but maybe it will be helpful)

What I've tried:
-disabling legacy USB in bios
-disabling HD onboard sound in bios
-powering on the system with each of my 4 ram sticks by themselves
-rebuilding the system and power testing as i added components (i.e. plugged in motherboard and powered on, added CPU and powered on, added RAM, powered on, so forth)
-Completely reformatted HDD (cleared EVERYTHING) and reinstalled Windows 7
-I replaced the Power supply after seeing that the board powered on every time i hit the power button after testing just the board/board and processor on two other <450w power supplies. Again, the CoolerMaster powers on at every press of the button, while for whatever reason, the Xpower 1080 didn't (It did with the MSI board, however.)
-I have tested the system with the 9600 GSO's in SLI, a single 9600 GSO, and the 5570, and the same things happen with each card installed.
-I have reset CMOS using the switch, the jumper, and by removing the battery for 30+ minutes.

I put a speaker in to see if it was giving any abnormal beeps. ASRock's FAQ says one short beep means everything is working properly, and I was getting one short beep every time I powered the system on. To test that, the FAQ also said 3 long beeps with no memory installed. So i pulled the RAM and powered it on again- 3 long beeps.

I've tried everything I can find. I've scoured over every plug, made sure drivers are installed, everything. I would really appreciate it if someone could help or offer suggestions, as I really don't want to go through the hassle of taking everything apart again and returning things.

If you simply took the time to read this, thank you for your time.

[Eagle5]

I've figured out that, for whatever reason, something doesn't like black backgrounds. When I reinstalled the OS, i didn't reactivate Windows 7 (lazy) so a few days later, the OS reminded me by setting my desktop to a solid black background and displaying "not genuine" in the lower right corner. I reactivated, but I didn't change the background back. I also figured out that making something happen on screen will bring the screen back up (i.e. pressing the windows key to make the start menu come up.) so I set the background back to the windows 7 default and now the screen doesn't fade anymore.

That being said, I still don't know why that happens. Just some more information.