I had this problem since day 1 but I finally started to look into the issue... I think it is memory related, but I can't start buying here and there memory just to try it. I guess this board is really picky since my ECS crappy board I got works with everything and S3 resume.

I tried :
Q6600
E4300
G.Skill 2GB TT Series memory (with 1.8 volt stock)
OCZ 1GB Platinum memory (those are 2.1 volt for PC6400)
Asus Nvidia 8800GT 512MB
Radeon X1600
Remove the Sound Blaster
Windows XP
Windows 7

So far, nothing worked. The only thing that changes is when I played with memory.
2X2GB G.skill : beep beep forever
1X2GB G.skill : continuous beep (never stops)
2XOCZ : no beep, everything seems to be going but total black screen.

I heard of common issues with Gigabyte board, is that true?

If you have any ideas... I'm about to replace my Gigabyte by my crappy ECS board soon.