I just open events, and in the filter checked checkbox "Show unknown events"

Undefined offset: 10103 [events.php:676]
Undefined index: [events.php:725]
Argument 1 passed to hostMenuData() must be of the type array, null given, called in C:\xampp\htdocs\2.0\frontends\php\events.php on line 726 and defined [include\hosts.inc.php:1312]
...

This issue checked in 2.0 r30450 and r31003 (Head revision (22.10.2012))