The player on the page that you linked to uses the Flash plugin.
Your More system details list shows the Shockwave Flash 10.1 r102 as installed, so Flash should be working.

Do you have problems on other pages with Flash?

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Themes).

• Don't make any changes on the Safe mode start window.

See:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

I haven't experienced problems with Flash on any other pages/websites.

I'm using the Default theme (have never changed it or installed any others).

I tried starting in Safe mode and got the same problem: when the page loads, it has the "missing plugins" notice bar at the top; the audio plays for a while, but no video, and then FF crashes.

Found a solution that worked for me and many others on Apple's discussion forum:

A post by joelmorris: «Hey! I had the same problems as all of you guys, but I got it working! All I did was right-clicking in the flashplayer BEFORE clicking the play button, and choosing "Settings". There I un-clicked hardware acceleration! And it worked! My problem have been with live streams like Al Jazeera, not Youtube. I'm using the latest version of flash: 10.1.103.19 and Chrome. Hope that helps! Joel » Original post on: http://discussions.info.apple.com/thread.jspa?threadID=2737231&tstart=0&start=0 See the last post at the bottom

Good luck!!!

I got part of my problem fixed. The "Additional plugins are required to display all the media on this page" warning was being caused by something on the page that requires RealPlayer. I installed that plugin and the warning went away.

At the same time, the video from the live feed also started displaying (I had been getting audio only), but Firefox still crashes after it's been going for about a minute.

I haven't been able to turn off the hardware acceleration option on Flash yet. When I right click on the window where the video content plays, the settings box is grayed out and nothing happens when I click anywhere on it. I'm still working on figuring out what the problem there is.

I finally got it fixed. See my last reply (above) for the fix for the "Additional plugins required..." bar issue.

To make the video display without crashing Firefox, I had to do what georgek above did: disable hardware acceleration in Flash. However, I couldn't do it in the Flash window on the Al Jazeera web page. Everytime I right clicked and selected Settings, the settings dialogue box was grayed out and I couldn't make any changes.

Instead, I had to go to http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager02.html. (Actually, any of the settings panels listed on the left navigation will work.) The settings panel box displayed there is a Flash window. I was able to right click (or CTRL-click) in the settings panel box, select Settings from the drop-down menu, and THEN I was able to uncheck hardware acceleration.

Hi - I tried the tip above but easier. If you right click on the flash player (or two finger click I guess in mac speak) you will see a settings box. "To make the video display without crashing Firefox, I had to do what georgek above did: disable hardware acceleration in Flash. However, I couldn't do it in the Flash window on the Al Jazeera web page. Everytime I right clicked and selected Settings, the settings dialogue box was grayed out and I couldn't make any changes. "

Same for all of us - but only - strangely - on Al Jazeera's page. In my Facebook account, where one of my games are that use the Flash player also (TikiResort) it is not grayed out and I was able to deselect it. When I went back to Al Jazeera I looked again - and voila! Deselected and AlJE is playing.

The other post suggested something more complex about going to Macromedia's site and doing the same thing - but it seems to me any other instance of Flash player will do.