I realize this is an old thread, but this problem is plaguing me as well (3+ years after this thread started). I am using the Kona LHi card with version 10.4.4 of the driver software. I’m not using any external decks nor syncing with anything externally so Genlock is on Free Run. In Final Cut Pro version 7.0, I get the crackling and popping it seems about every 20 plays or so. Also, even after I hit space bar stopping playback, the crackling continues and then “fizzles out” after a few seconds. Also, it seems to be slightly amplitude related. In other words, if a piece of audio is a little louder than another, it crackles just a little more than parts of the program that are softer. I just played a video for a client and I heard it throughout…but it was fairly faint. Luckily the client didn’t notice it.
Every time I get it, I can stop playback and start again, backup to the same section, etc and it’s nice and clean. It’s like there’s some “dirt in the fuel line” or something? If anyone has found a solid fix, please post it here. It would be much appreciated!