We have the same problem – can’t edit to tape using a DSR-45 and DeckLink Extreme card. We’ve tried to do it via Firewire and the deck isn’t even recognized. We get the spinning beachball if we have our Firewire LaCie drives connected along with the DSR-45. Called Apple – we did a hardware test (no problems!) and reinstalled the OS as they said. No improvements.
Is there a conflict with having the Decklink card installed and trying to output via Firewire? We can edit to tape using a Beta SP deck, but for this situation we need DV cam.