Google:

Issues: There are a few issues with exceptions to recurring events in Google.

1. If you create a daily recurring event and move one of the instances to another day (so that two instances occur on the same day), the wrong exception information will be sent to the device causing differences in what the server and device show.

2. If you sync a recurring event to the device, make an exception on the device by modifying an instance and then change the recurring series (not the exception) on the server, the exception will be removed from the device.

3. If you edit the day and time of a recurring series on the server, any exceptions revert back to the master settings of the series.  During a subsequent synchronization cycle, the exceptions will be removed from the device as well.