Appointments showing as meetings only in Outlook 2011

I am using Outlook 2011 on my MAC and Outlook 2010 on my PC both connected to a 2010 Exchange Server at a hosting site.

Now, I have 237 appointments (out of 10100) that show as meetings ONLY in Outlook 2011 on the MAC, BUT show as normal appointments in Outlook 2010 on the PC and on the exchange server using OWA.

I do not use meetings and I never created a meeting, so these have been switched over probably while trying to sync with an Android phone! THAT is another question altogether!

Is this a bug in Outlook 2011 or are these really meetings that OWA and Outlook 2010 do not differentiate?

How can I "bulk" change these back to appointments in Outlook 2011?

Thanks.