Classifieds plugin possible theme conflict

I just installed the classifieds plugin on my site and there seems to be some issue with my theme. On the classifieds page it puts ClassifiedsClassifiedsClassifieds......all the way across where the main navigation is. It's just text but I'm not sure where it's coming from. My theme uses categories to build the main navigation, could this be a problem? I've attached a screenshot so you can see what I mean. It's only on the classifieds page and not on the single listing page.