Even though the Enermax is normally a good PSU I wouldn't be suprised if your initial problems were down to that rather than the board. Most of the double boot issues are from the PSU, not all but a lot.
I notice you have managed to hang on to a revision 1.0 board. In m my opinion much better than the revision 2.0.
i did post issues on here and other places everyone was stumped, but there was issues on the DXX destroying HDD,cdroms, graphics when i searched after swapping out Psu , the Cap wine was very bad indeed , the noise you would blam it on board straight away as it sounded like it was untill i took the Psu out and booted system..
i did not no that most of the Double boots are down to the Psu, the HX850 should do the job just fine as that is what i asked for when i refused the DXX, the Hx is around same power, i did not want anymore refurbish rubbish, this is Retail sealed., is there anything eles i need to no that can throw off the Mit?
i no it was before the 2.0 release though, would be gutted if i had an issue again and got the 2.0 16 phase version, the Ud7 1.0 is basicly a Ud9 .
one thing i did take the Water block off the northbridge , this dropped temps around 5-6 c on air and using the Passive cooler, also want to copy the Ud7 2.0 heatsink for the northbridge, got the low profile heatsink i jst needs cutting and then get a thermal pad, just to see if i get a temp drop again.