Konqueror can not handle HTML

[Michael Schmitz <michael@cityweb.de>]

Since I've upgraded to KDE 3.1 (Karolina) I got the following message when I 
open a HTML file with konqueror while in file browsing or ftp mode:

"There appears to be a configuration error. You have associated Konqueror with 
text/html, but it can't handle this file type."

Web browsing works fine.

With google I've found some more messages from people having a similar problem 
but no solution. And they are some month old and not related to a 3.x 
version.

Any ideas?

Thanks in advance
Michael