Hi Dave,
This is what we suggest doing:
1) IMPORTANT: Back up your Google Calendars and Outlook PST files (always important whenever installing new sync/calendar software)
2) Uncheck the calendars and sync again. (This will unsync the calendars and the synced items will be removed depending on where they came from. Items from Google will be removed from Outlook and vice versa)
3) Uninstall OggSync
4) Upgrade your Outlook
5) Reinstall OggSync
6) Recheck calendars, sync again
7) Do a test sync to make sure everything is working ok.
We are suggesting to unsync during the upgrade, however, if you wish to test keeping the sync state between versions, you could skip step 2 and 6, although we aren't sure what Outlook does during an upgrade of a PST file, so results of doing that are unknown right now.