Beer might have been safer - I'd have known I was impaired and quit while I was ahead instead of trying to get clever.  :

Only a small thing. Thx Dandello. In germany we drink a beer at this time or two or ....... 

ThM pointed out an error and I fixed it - too much coffee and no breakfast is always a bad combination.

Your RSS feed here is working fine for me, including the listing of the sub board test.

Some things just can't be properly localized. 

AACK!!

At this moment here in the board. clicking on rss button at the to right side of the board (Board Index) but i receive no messages

Found another bug 
New zip:

Okay, finally got it to read subboards for the categories and the whole forum.  Here's a copy of RSS.pm currently running here:

It doesn't seem to be a problem here, but it is elsewhere - the RSS Feeds for Categories and for the whole forum doesn't show the proper number of items.

Now, there doesn't seem to any particular rhyme or reason to this. Sometimes changing the RSS settings seems to fix it - and sometimes not. Sometimes refreshing the browser cache seems to fix it.

Here is a fix for testing: In RSS.pm find

            $threadcount = @threadlist;
             if ( $threadcount < $topics ) { $topics = $threadcount; }
             @threadlist = @threadlist[ 0 .. $topics - 1 ];
         }
     }

     for my $i ( 0 .. ( @threadlist - 1 ) ) { 

and replace with

        }
     }

     for my $i ( 0 .. $#threadlist ) {
         if ( $i == ($topics - 1 ) ) { last;}
  

The RSS feed for Category and for the whole forums also doesn't show the subboards.  So that's on the bug fix list.