Thank you for the provided technical details of the difficulty you've encountered, and sending the diagnostic feedback to our email. Most probably, the issue is related to hanging of Mac OS Sync Service and could be fixed by the correct restart of the driver (http://support.apple.com/kb/TS1627
For further troubleshooting of the issue, please try to proceed a driver restart following the below steps:
1. Download the specific interface for Sync Service, called iSync. It could be downloaded from:http://dl.dropbox.com/u/35834399/iSync.zip
2. Extract the archive and copy iSync.app to ~/Applications folder.
3. Launch it, Sync Service icon will appear in Mac menu bar.
4. Close all other applications.
5. Hold the Option key on your keyboard and click the Sync menu in Mac menu bar.
6. Choose "Reset Sync Services..." option.
7. Reboot your Mac.
After performing of these steps the sync process should start working without a problem.
If it still fails, please try to manually create an event in Google account, using web interface, and let us know the result.