I finally gave up on the clunky 2010 Outlook/Calendar sync and moved to Thunderbird+Lighting/Provider for Google Calendar.
The TB sync process just seems to work better. It's pretty cool to add a calendar entry on your iPhone, and watch it populate your GMail calendar and your TB calendar (AKA Lightning) almost simultaneously.
Oh and Outlook 2010 was just rubbish with GMail IMAP accounts. Rubbish.