Getting 301 (moved permanently) error, when posting

Hi,

we're encountering a strange problem in our forum (vbulletin 3.6.8) when vbseo 3.0.0 is active (url rewriting) under Tink.ch :: Forum

As soon as someone wants to post something (i. e. a thread) the following message appears:

Moved Permanently

The document has moved here.
Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.
Apache/1.3.39 Server at tink.ch Port 80

It used to work. However, our provider has upgraded some software (apache, php, mysql etc.) on our managed server. And I believe that the error message above appears since then.

But I haven't got a clue how to find out where to start searching for. What else would you need to know in order to be able to help?

Many thanks for your speedy reply. Unfortunately, the option "Add standard HTTP headers" doesn't do the job.

Observed the following behaviour in addition to what I've described already:

As the error message appeared I reloaded the page and confirmed the post to be resent. After that I'll get the automatic redirecting page. On that one, the manual link is correct but if I let the server do the redirecting automatically I'll get the same error message like the first time.

So, instead of redirecting for instance to Alkohol und Tabak - Tink.ch :: Forum
the server automatically uses this one here: Tink.ch :: Forum

Any idea where else I might get a clue to solve this problem?

Yes, it does.