I have much the same issue and did the uninstall and updated to MM 4.15601 also. My phone synced once using the Beta program and I have used my Ipod and Walkman since, thinking a bug fix would come along. I have iTunes 10.1.6.7 installed, haven't changed to 10.7 yet. Also have not updated to IOS 6. Edit-updated to 10.71 and no change.
At times MM will find my phone and even try to sync. I get an error message that I don't have enough space-wrong lots of space. It doesn't try to remove songs not in the new sync so must not be reading my iPhone song list. When I tell it to go ahead even though there is not enough space it goes through the motion and then provides a long list of songs that didn't sync-nothing changes on my iPhone. Removing the auto sync MM brings up my phone and the directory-songs, playlists, etc.- but it won't go deeper to list any songs.
Is there a way to delete my iPhone from the sync list and start over as a new device? Any other suggestions?
I may try another trouble ticket, but the last one didn't offer a solution that worked.