Have you done a resolve place names on the affected records?
FTM (the program) has an internal Place Name Authority of about 3.5 million places. This has nothing to do with Bing maps but is used when you resolve place names and the new places hierarchy functionality
Have you compacted your file?
I once lost an FTM file once because of a power glitch that so severely corrupted the file I could not fix it. I had good back ups.
I then purchased a Uninterruptible Power Supply (UPS) to protect my computer and modem
I would suggest that you focus on getting your FTM data correct before you contemplate syncing