This file is missing:
http://www.catzzz.net/htsrv/comment_post.php

did you rename your htsrv folder?

Not to my knowledge 8|
Great hint, will see, if I can solve that...
Thanxalot
eliZZZa

Hi Personman,
the file exists, the htsrv directory is set to CHMOD 710 and the file comment_post.php to CHMOD 740 - same permissions as is eliZZZa.blogZZZ.net, where everything works fine...
Do I have to change permissions?

Kind regards from Austria
eliZZZa

Probably. Try it and see if it helps.

Just for testing set both, the dir and the file to 777 - no change.
Calling the file directly, gives a "no permission" error.
Sending a comment, just does nothing...
Hmmm...???

I'm still getting the error, too. Seems like a server problem. You should be able to call the file directly. The file will output something like this:

Parameter comment_post_ID is required!

But a server error is a server problem. Check with your web host, maybe.

It was the .htaccess!

Great thanx for your hints!
eliZZZa

Cool. Glad to hear that it's working.

I can access the file directly now and I am able to post a comment out of the admin. But nothing happens, when posting a comment from the frontend. Any further idea?
Thanxalot
eliZZZa