Problem
After a few minutes of deliberation I finally figured out the cause and solution. The Zune software was trying to sync a song from the Zune HD to the computer. The song was corrupted though (played the first few seconds then stopped).
Solution
- Disconnect the Zune HD.
- Find the most recent song the Zune Software was attempting to sync and check that song (on the Zune HD) if it is corrupted.
- If that song is corrupted (or has problems playing) long press and select delete. Otherwise you'll have to go through your library and find what song file is causing the problem manually.
- Plug the Zune HD back into the computer with the cable and everything should be back to normal.
Best of luck and feel free to leave a comment if you have any questions.