Calendar module not updating correctly from remote Google Calendar

I am using a remote Google Calendar to schedule events in the calendar module, and I deleted some events yesterday, however they still appeared in my PBX calendar - I checked more carefully and they had been deleted a week later than the date I had actually deleted them! I ran fwconsole calendar --sync and each calendar says "skipping", however when I run rm -f cron.error followed by reload it says "Done". The error is still there (event deleted a week later).