I finally got my Motorola A630 to work with iSync. Here's what I had to do...
- Quit iSync if running.
- In the Finder, press Command-Shift-G to get the Go to Folder window, and then enter this path: /Applications -> iSync.app -> Contents -> PlugIns -> ApplePhoneConduit.syncdevice -> Contents -> PlugIns -> PhoneModelsSync.phoneplugin -> Contents -> Resources. Alternatively, you can Control-click on the iSync application, choose Show Package Contents, and then open each of the above folders.
- In that folder, duplicate MetaClasses.plist so that you have a backup (you'll probably want to undo this process before you apply any upgrades to iSync...).
- Open MetaClasses.plist with TextWrangler (free from BareBones).
- In that file, after the opening <dict> line, insert this code.
- Duplicate any one of the Motorola TIFF files in that same folder and rename it MOTA630.tiff (or just use this file).
- Launch iSync and enjoy!
This hint worked both before and after the iSync 2.1 update (though I undid it before applying the update, then re-applied it).