[TYPO3] Cal Ext. and UTF8 Problem

[Matthias Gottschalk]

Hello,

sorry my English is very bad, but i have a very big Problem with the Cal 
Extension.
The month "March" in German "März" has a false presentation of umlauts.
My Typo3 Config is correct: config.locale_all=de_DE.UTF8
The Database & PHP Settings are correct too:

Language: German de-utf-8
MySQL Carracter Set: UTF 8 Unicode
Carracter Set: UTF8 general ci
What seems to be the problem?

Please help me, I am at a loss what to do!

Best wishes
Matthias