Not wanting to hijack your thread, but I have the same problem, I have lodged a call with support, and been directed to the sync problems page.
Things I have tried without resolution
1)Unlinked, and downloaded a fresh version from AMT
2)Deleted online tree and uploaded a new one
3)Tested with a test tree, no media
4)Sent a error report to support
5)Uninstalled FTM, and reinstalled
6)Its not an firewall issue, happens at work or at home, and has worked in the past, stopped about 10 days ago
7)Syncing manually not automatic
8)changes made online sync properly, not the other way around
Things I have tried without resolution
1)Unlinked, and downloaded a fresh version from AMT
2)Deleted online tree and uploaded a new one
3)Tested with a test tree, no media
4)Sent a error report to support
5)Uninstalled FTM, and reinstalled
6)Its not an firewall issue, happens at work or at home, and has worked in the past, stopped about 10 days ago
7)Syncing manually not automatic
8)changes made online sync properly, not the other way around