Lately it seems that more and more popups are managing to get through Firefox. It seems that the Macromedia Flash plugin allows Webmasters to launch popups in a way that bypasses Firefox's built-in blocking mechanism. Simply follow these steps to disable this annoyance:
1. Type 'about:config' into the Firefox location bar 2. Right-click on the page and select 'New->Integer' 3. Name the new value 'privacy.popups.disablefromplugins' 4. Set the value to '2'