Hi Tom,
Can you upgrade to the latest mojoPortal? I didn't realize that it was not compatible with your version. Sorry for the inconvenience.
If needed let me know and I'll send you a copy of Event Calendar Pro 0.0.3.2 by email, downgrading to that might solve the error (there are no database differences so it should downgrade ok to that version) but you'll be back to the skin problem with that version.
Best,
Joe