Thank you
You appear to have a large number of plugins installed (Extensions -> Plugin Manager). May I suggest uninstalling any plugins which you are not using as they may be causing a conflict with your calendar form. Also worth removing any modules which are not been used. The following articles details how you can remove the demo module positions...
http://www.joomla51.com/tutorials/item/cleaning-modules-from-demo-installer
Finally try temporarily disabling modules on your form page to ensure there is no conflict there. Failing that please get back to me and I will take another look.
Regards
Ciarán