Since I'm guessing iTunes 10.5, iTunes has started to sync the same Genius data for the same 315 songs with every sync.
I use Genius and want it to work as advertised.
So, I turned off Genius and on again.
I restored the iPhone.
I knew the next step would tke ages, and it did: find and remove those tracks.
I looked for logs but it seems there aren't any, so I found each track - with the help of Snapz Pro to check the names of the tracks as they flash up - and removed it from the library. Several hours later that had "solved" the problem, and I turned Genius off and on again as well to resync.
But, when I add the tracks back, same problem. (In fact, it was 314 tracks and is now 315.)
What seems to be the issue is that these tracks are near-duplicates: so remixes of the same song (with the full remix name in the title) or the same song on an album, and let's say a greatest hits collection. (I would love it if iTunes could somehow applytwo sets of metadata to tracks so they'd be picked up as both when playing by album, but it does not, and I do play by album from time to time.) But, all of the tracks - including the "original" - need to be deleted. So, if I have a single with four mixes, Genius will keep syncing even one of those tracks if I delete three. I think these tracks may not have been purchased on iTunes - I see a lot from Napster (new version! Becks beer has been giving free tracks!) and some from my pre-iTunes CDs.
This is not the end of the world but it is annoying. Has anyone found a fix? I see other people reporting what I think is the same problem, but the suggestions are the usual things about turning Genius off and on again. I think the problem is likely how Genius deals with very similar tracks: badly, is my guess!
The reason I wanted to do this was I have been planning to enable iTunes Match but wanted a "clean" library to start with. On the one hand I'm wondering if iTunes Match might replace some of these non-iTunes tracks with the iTunes versions; on the other hand I'm guessing it uses the same library, and thinking out loud I wonder if it is finding "duplicates" to lighten the server load?
Anyway, thoughts and comments would be appreciated.