Hello!
Having the same problem with the squealing =(
I bought a Rev 1.0 UD3R, than RMA'd it and got rev 2.0 and still had the same problem with the squealing. I tried different PSU's but nothing helped.
So i sent it back again... later got some guy raging at me that it is my fault and i'm doing something wrong, but agreed to order another board for me (hope it will be rev 2 again, don't want 1.0).
However, i think i'll have the same problem with the next mobo and i dunno what to do, i believe i won't get another after this, 4-th MB =). And i don't have any other options other than Gigabyte. Asus is too expensive, MSI is kinda lame...
I'm stuck, and i can't upgrade to UD5, cuz it's the same there too, from what i read on the net =)).
PS The second motherboard had the usual squeeling from the board itself, and it also had the exact same sound from the headphones, that's some nasty stuff... can drive you nuts =)