I had a sync problem with FTM2012 media coming up with a process error. I sent a request to Ancestry Support, who took 2 messages and 3 weeks to tell me to use the troubleshooting tips in the knowledge base. As part of that I ended up deleting the on line tree and uploading again. I then ran the SyncErrorReporter and searched the text file generated for the word "error" and it highlighted a problem with one particular media file. I fixed it in about 10 minutes!