This is not a normal situation and we have never seen this happening in any of our customer's site. I was wondering whether there is a conflict between the styles that are used by the qDiscussionView web part and your master page. Did you ever modify your master page? Did you use any 3rd party control in your master page? We use 3rd party control from DevExpress and Telerik in the qDiscussionView. Maybe you should analize whether there is a conflict in the styles by analizing the css files that are included in the HTML source.