First, let me be upfront that I have NO knowledge of the internals (SW architecture) of FTM 2014 (or any of the FTM products). As as software engineer that enjoys genealogy I started to look more closely at the sync issue everyone is having (myself included). Many folks were reporting that they were told to delete their Ancestry tree and then upload a new copy. I tried another option last night on a suspicion of what might be happening and need to get someone to replicate the process to see if it clears up the sync issue.
When you upload, link and sync an FTM file to an Ancestry tree, it creates a sync file on your local system (ends with ".sync" and is in the same directory as your FTM files). I started to suspect the problem might be a corrupted sync file as evidenced by the strange date that sometimes shows up in FTM for the online tree date (indicating some bad data). Instead of deleting the old Ancestry tree and reloading the FTM copy, I instead renamed the old sync file and forced FTM to upload a new copy to Ancestry (and link it). That action caused FTM to create a new sync file whereas deleting the old Ancestry tree and uploading a new copy would not necessarily create a new sync file.
So far, I haven't had any issues, but have not had time to make many changes (via FTM or Ancestry) to see if the problem is completely eliminated. I thought I would post this to see if anyone would like to replicate this to see if the problem is resolved.