I installed 1.8.3 premium version. Plugin seemed to be working, but doesn't matter how many times I try to post, the post returns blank page (page HTML not fully loaded).
Then I deleted and installed 1.8.2 but that crashed my whole site to 500 internal server error. For now, I've stopped the plugin to keep my site running.
http://wordpress.org/extend/plugins/all-in-one-event-calendar/