I'm using Firefox 36.1 and on some sites a page will not load and it says javascript:void in lower left hand window.
1. I've found that unless I click directly on the link and let it connect however it wishes to (vs trying to open the link in a new window or tab), I often get exactly the behavior you describe.
2. Update your version of Firefox to 36.0.1 (if you have already as suggested by artie). It might help.
