Thanks for the help.
Bug #58640 must have been the cause. But as I am not so fluent about
mediawiki the patch info was not so helpful. Instead I checked that it
has been solved in mediawiki 1.23.6, so I have upgraded to this version.
And, of course, it works perfectly.
--
Tommy Pollák
Wiboms v 12, 2 tr
S-171 60 SOLNA
Sweden