Just in case someone else has this issue I was able to fix it using the instructions
here. The second resolution involving the Terminal command is what did it for me.
Resolution
Reset the SyncServices folder with these steps in Mac OS X 10.5:
1. Open iSync.
2. Choose Preferences from the iSync menu.
3. Click Reset Sync History.
If this does not resolve your issue, or if you are unable to open iSync, follow these steps:
1. In the Finder, choose Utilities from the Go menu.
2. Open Terminal.
3. In the Terminal window that opens, type or paste the following command on a single line:
/System/Library/Frameworks/SyncServices.framework/Versions/A/Resources/resetsync .pl full
4. Press Return.
5. When the operation is complete, quit Terminal.