I am glad i posted in the newbie forum, cause then it is more ok for me to say that after trying everything i could find and googling around I till don't know how to check the error-logs or how to check the permissions.
Your advice makes good sense though. i just found out that I can't write to my Google calendar that is also synced into Evolution. It shows up and I can read the entries but i cant create new appointments.
A bit more explanation please