BSOD and troubles going in and out of sleep mode - Minidump attached

Hey all, my first time to the forum, looking for some help from some of you Windows wizzes.

I have an Athlon 1090T, 4gig eco g.skill ram, 6850HD graphics, Windows 7 Home Premium 64 bit. I put it together myself and while things didn't go smoothly I have been working out the bugs. The main problem is that it won't take 8 gigs of gskill ram and I need to mess with the timings when I have time. As of now though, I haven't messed with any timings and the ram that is there passes 5 rounds of memtest.

All of a sudden I have a new problem. Lately maybe 1 time out of 4 when I turn it on, it does not boot. All the fans run, I can hear the drive being accessed, but nothing on screen and no POST codes on the motherboard (it has LED). To fix that, all I had to do was unplug from the wall for 20 seconds, plug back in and it would go again, everytime.

Then just recently, whilst playing a 3D game, it crashed, and upon reboot started making a buzzing noise near the power light. It booted windows before BSODing (minidump - http://dl.dropbox.com/u/1767436/091811-15818-01.dmp).

My power supply is good quality, one of the midrange corsairs I think, and everything is brand new. I wanted some help with the minidump to see if I could rule out some things. If it is the power supply, I am a little lost as to how I would find out or test it.

I know next step is to open it up and examine all the capacitors, the motherboard etc for damage, but I have never smelt any burning and havent OC'd.

Cliffs:
1. Strange power anomaly where 1 in 3 or 4 boots it wouldnt POST but everything ran, fans and drives etc
2. Crash during Left 4 dead 2
3. upon reboot there was a buzzing noise near the power light and then a BSOD after a minute in windows.
Here is the mini dump - http://dl.dropbox.com/u/1767436/091811-15818-01.dmp

Just saw the BSOD posting guidelines. I will endeavour to make the appropriate changes to my thread but am going out now so bear with me :)

Ok I followed all those steps. It said it found and fixed corrupted files. Here is the results in the CBS log file (I hope it is ok to post this).

http://dl.dropbox.com/u/1767436/CBS.zip

No, I have only been running for a bit though. I guess I should give it a few days, run it through the ropes again and see how it goes? Play some games, maybe run some benchmark programs?

So could that have fixed it. Can problems in Windows cause the computer to sometimes not POST properly or have the weird buzzing sound on reboot?

Ok, will do. It wasn't from the speakers. But if it happens again, I will post back with all the details.

Ok, the buzzing happened again. It happened when I was running a 3D benchmark tool. The Heaven benchmark DirectX11. The sound seemed to be coming from this little blue light (http://dl.dropbox.com/u/1767436/PC-Image.jpg).

I later ran superPI and got the CPU going full pace and didn't get the same problem. So it could be the graphics card, or the connection or power to the graphics card? Oh and I still got another instance when the computer seems to boot but the monitor remains dead.

I also ran a diskchk in the mean time and found no errors.