JS Loop in Firefox, page not responding

Unfortunately your plugin “Product Filter by WBW” causes a JS loop in Firefox. The filter is never fully initialized and the site stops responding.

Page with problem (please use Firefox): http://11548.31751-2.whserv.de/sortiment/spirituosen/800/

Can you please have a look at it and fix the error?

Thanks and best regards,
Alex

The page I need help with: [log in to see the link]