I too have been suffering this issue
I'm using an A4-3500, with crucial RAM under win 7 x86 (tv tuner wont work in x64)
I checked the initialise VGA BIOS setting, but found it already set to PCI-E. Switching to onboard made no difference. I have, however, just had three straight successful wakes using the failsafe defaults. *crosses fingers* - I hadn't switched BIOSses yet, so I'm still on F2.
Alas, I don't have time for a BIOS option witch-hunt this afternoon, nor time for some proper testing...I'll monitor this thread, and will try to get back to you over the coming days.