ITunes refusing to sync (wrongly thinks it is over capacity) after iOS5 update

Question

After updating my iPhone 3GS to iOS5, I started running into a problem (actually many problems like broken 3G internet but not directly related and I fixed those).
What lead to my current sync problem was initially a "An error occurred while restoring this iPhone. (-34)" infinite loop, described in other posts here as a common issue after iOS upgrades going back years (good job Apple). Out of frustration and to get out of it I ended up deleting my backup, which solved the loop but has now left me unable to sync.
According to iTunes, my phone has no music on it, but in fact it has 22 GB of content (out of 28 capacity). I figured since it thinks the phone is empty I'd just resync everything (a very long process, but until I do it I won't be able to sync at all) but after applying my selection for synching (specific playlists, 128 kbps AAC encoding, etc) iTunes fails to sync and tells me my selections require another 15 GB of space, even though the capacity bar for my selection says 22 out of 28 GB used (which is exactly what the bar said before I updated to iOS 5). What these numbers suggest to me is that even though iTunes doesn't recognize my music as still being on my phone, the sync process itself does and is trying to copy 21 GB of data into 6 GB of free space, resulting in the -15 GB error).
Can I make it recognize those files as already being there (to save myself having to copy them again) and if not how can I have iTunes clear files it doesn't report as being present? Preferably without wiping everything else that's on my phone, such as text message history etc.

Answer 1

Hi mforsayeth!
Here is an article that can help you address this issue:
iOS: "Not enough free space" alert when trying to sync
http://support.apple.com/kb/ts1503
Thanks for being a part of the Apple Support Communities!
Cheers,
Braden