We have JEvents 3.4.10 with the Anonymous user event creation plugin. It's been in place for a while now and working fine, but we're finding that all of a sudden, when a user goes to select a date using the picker the selectioin window that opens is very funky and spreads across the entire browser window.

You can see it here: http://www.episcopalmaine.org/index.php?option=com_jevents&view=icalevent&layout=edit&Itemid=314

Any idea what is causing this?

It seems to happen across several different browsers (Chrome, Firefox, Safari at least)