I have almost the same problem – the card is just not responding at all on windows7 ultimate 64bit…
I tried a different workstation: XP 32bit and it worked with the old decklink software which came with it- as soon as I installed the new 7.7.2 in XP the card was seemd to be no longer there as well.. the blackmagic control panel is all grey and non responsive..
all done in admin mode…
what can it be??
really frustrating this…