Marco,
I have had this problem as well. I am using a Miranda VTR-100 to convert my UVW-1800 Beta Sp deck to SDI and SPdif. I have a Decklink HD Pro card into a G5 with UL4D with Huge storage as well. While capturing, I always get crackle, once the footage is captured it plays fine. I am using a Dolby digital surround decoder into a Dolby CP series distributor. I can’t figure out what the issue is. Any ideas from Blackmagic?
-Bryan