Karen,
I activated Community, all of your plugins are updated to 3.1, and I’m not seeing the error any more. I’m not sure if you changed something, but it seems that the issue is no longer occurring. Can you confirm on your end? http://southernarizonaguide.com/events/community/add
I also noticed some formatting issues with your current theme, so I added some custom CSS rules to fix it.
Take a look and let me know. Thanks!