Events Manager 5.3.2 seems to be missing a changelog here on WordPress.org. It can be found at http://wp-events-plugin.com/blog/2012/12/11/5-3-2-released/ and reads:
This release fixes one issue, which occurs if you are using MultiSite and our global tables mode with the newly released WordPress version 3.5.
I you are using the above setup, upgrade to 5.3.2 now.
Big thanks goes out to Fee who spotted the problem and persistently tested this to figure out the cause (and solution!).