Summary:
Must have "To Date" set for event in Internet Expolorer
Detailed Description:
In Internet Explorer (I have version 8) it is not possible to add or edit event
if the "To Date" checkbox is not set.
If the "To Date" checkbox is not set all fields and buttons below that checkbox
disappears. This means that it is not possible to add or edit events.
Workaround: Use other browser, e.g. Firefox, which works.