Check this page:
http://validator.w3.org/feed/check.cgi?url=http%3A%2F%2Fwww.fusselblog.de%2Findex.php%3Fblog%3D1%26tempskin%3D_rss2

I don't know exactly what the problem is, but maybe you can try to tweak the post that creates the problem.

Also I recommend you upgrade to v5. It may or may not fix your problem, I don't know, but soooo much has changed since v 4.1.6...

Perhaps I should update - but I don´t understand, why that only appears on the blog that shows every entries. When I chose a single blog, everything is ok.

http://validator.w3.org/feed/check.cgi?url=http%3A%2F%2Fwww.fusselblog.de%2Findex.php%3Fblog%3D14%26tempskin%3D_rss2

Could it be, that the server is too slow to create the rss?

No I don't think so.

I fixed the problem!
I searched at the wrong end.
The MySQL was too big and over the limit of my ISP. I changed the MySQL to a bigger one and now everything is working again.

Thank You for the help, an update to version 5 is planned, but I must take a free weekend, because the Fusselblog is so big an I think I must fix the template after update from 4.1.6 to 5.0.5

The RSS doesn´t function again. Perhaps this can say, what happens:

Warning: MagpieRSS: Failed to parse RSS file. (undefined entity at line 80, column 31) in /homepages/29/d13516195/htdocs/fusseltuning/fusselforum/rss-fusselblog/rss_fetch.inc on line 238

What can that be?

I tryed an update to 5.0.5 on a copy of the blog, but that also doesn´t function :-(

Forget the error message from last posting -- its in another script, that tries to catch the RSS from my blog.

I fixed the problem again.
There was one Blog, that made these Problems. Everytime I wrote in this blog, the RSS made problems. After 5 newer entries in other blogs, it works again. So I can´t find the problem in this blog, I moved all entries in another blog and now it works again...

Have you looked at the link I gave you above?

I found the mistake: Therer where German "Umlaute" in the Names of the categories. These made the bugs...