Hi,
Thanks for posting, I am happy to help. I am guessing that you are using OSX 10.7.4, with the latest version of iTunes. When Apple made their latest updates it broke drag and drop support for our older software. For now I recommend dragging the iTunes Music folder into MIK to analyze files. I'm hoping that we can get an update for MIK 4 out in the next few weeks to solve the problem once and for all.
Cheers,
Chad P