After doing some playing I found it will work as long as you don’t use above 3.5GB ram. This is on a 4GB ram setup. Under 3.5GB it will work okay above and it will not respond. This is on PCI Decklink SDI.
It works fine on 32 bit which is what I’ve been using and does not work under 64 bit. Only moved to 64 bit in preparation for CS5. So at the moment this is a big problem as Premiere Pro and After effects are native 64 bit.