This problem can be caused by pages that use Flash media. Here is some standard guidance that addresses the most common reasons for Flash problems in Firefox. I'm sure you've seen some of it before, but just in case: (1) If you have installed any recorders/downloaders that interact with Flash media, make sure they are as up-to-date as possible, or disable them. (2) Disable hardware graphics acceleration in Firefox and in Flash (A) In Firefox, un-check the box here and restart: orange Firefox button (or Tools menu) > Options > Advanced > General > "Use hardware acceleration when available" (B) In Flash, see this support article from Adobe: http://helpx.adobe.com/flash-player/kb/video-playback-issues.html#main_Solve_video_playback_issues (3) Disable protected mode See this support article from Adobe under the heading "Last Resort": [http://forums.adobe.com/message/4468493#TemporaryWorkaround Adobe Forums: How do I troubleshoot Flash Player's protected mode for Firefox?]

Actually, I assumed you already checked the following article but, if not, please check this first: [[Firefox can't load websites but other browsers can]].