iTunes 9.2: “The iPhone cannot be synced. A duplicate file name was specified.” AppleToolbox – Tools and Fixes for Mac OS X, iPad, iPhone and iPad. Seems that removing iToner is the key. Instructions in the link above. If that doesn’t work try this. It solved the issue for Flynn0r.
“Uninstalling all the components:
- Apple Application Support
- Apple Mobile Device Support
- Apple Software Update
and re-installing iTunes x64 did the trick. It´s working now!”