What causes audio to crackle and pop once it's imported. This is happening whether it's from a DV tape or a CD.

Could be your soundcard!

 Are you using a Mojo?  I've had weird audio issues before when I had the Mojo on an add-on firewire card as opposed to the integrated firewire bus on the motherboard.

No, I'm not using Mojo. I concidered the possibility that it was the soundcard except that the crackles and pops carry through when exporting and creating a DVD.

http://avidtechnology9

Try this link

 It could be that when in a timeline there are diferent sample rates (32, 44, 48 ) sometimes in the points where they change from one to another there happens these "pops", it happened to me a lot until i change all the sample rates from ALL of my audio to 48, from then on , no problems.

Changing the audio rate seemed to help.