Weird, because I checked the entries in the suhosin.ini and noticed, that all lines commands are commented out.
Anyway, now it works !
Two last questions: I realized, that when the Joomla cache is on, JEvents writes a lot of files in the JEvents cache folder. To much IMHO, because after a few days there are more than 100000 files in the folder. How to prevent this, please?
Next thing is, that I'm missing my RSS picture under the JEvents latest module. Do I have to switch on something?