I always see it, but generally shortly. I always presumed it may be due to media scanning on the phone. You may want to submit a debug log (under Options) from MMA as it may have captured the problem.

Note, some users have reported eternal media scanning activity on their phone (something I personally only experienced once: http://www.ventismedia.com/mantis/view.php?id=11013).

I see this from time to time. MMA displays that message for a few seconds (maybe up to a couple minutes) before starting to sync via wifi. I'm not sure if it's saying that the phone needs to finish something or MMW is busy. In any event, it usually finishes after a short time and the sync starts as normal.

I've seen this issue come up in a few threads. Basically, quite often when attempting to sync, MMA will go into this endless scanning. The only workaround I've been able to find is to uninstall MMA, and delete the folder from the phone along with all music files.

I'm using MMA .146 on Galaxy s3, and MMW .1644, and it's been doing this each release. Has a better workaround been found?