Time behaves odd in civiEvent

I have changed the date format in the global settings according to the on line documentation to reflect European date format. This works fine, but when creating an event the end time of that event will show a little bit strange depending on how I configured the date format.
Given the Date Display "Complete Date and Time" %d %b %Y, %H : %M (and same string in Input) the end time for an event shows strange values IF the date for start and end is the same.
If I remove the space befor and after the colon between hours and minutes the end time shows in twelve hour format with AM/PM IF the end date is the same as the start date, but correct with 24 hour if the start date and end date are different.
Guess this lies within the template of that page?
I run civiCRM 1.9.11960 on Joomla! 1.5 RC3.