Not sure if this is a bug or by design or what. I will frequently get added to someone's Google calendar at my gmail address. GSM will often fail at either bringing that event into Outlook or complain that it can't update the Outlook even back to Google. I get the merge prompt and the only option is Skip or Cancel. What would make more sense is if you have the option to Delete Google or Delete Outlook or Delete Both. Note that I generally see these on events that have already occurred -- but I can't be 100% certain. Usually, deleting the Google event on Google manually solves the problem.