Hi.

Now i had a look at your website BUT the problem is completely different from the one that you pointed out.
The link is not altered and that's not the problem, the problem lies outside Responsivizer too,in the menu item that is not published and available on mobile with ID = 490

The link:

Code:

http://www.modellbahnfreunde.ch/index.php?option=com_weblinks&view=weblink&id=36:sbb-a-3-5-601-649&catid=110:wikipedia&Itemid=490&task=weblink.go

points to the menu item with ID 490 and i assume you have excluded it in some way from the mobile website, indeed if you remove it and open up on mobile the link without it the link works:

Code:

http://www.modellbahnfreunde.ch/index.php?option=com_weblinks&view=weblink&id=36:sbb-a-3-5-601-649&catid=110:wikipedia&task=weblink.go

So i think that you have setup 2 different menus one for desktop and one for mobile, but weblinks links don't change accordingly so the menu Itemid on mobile is the same as on desktop, and if the menu is not accessible this explains the error.