Firefox video issues (html5)
Stacey started a channel on youtube with an introductory video that was in mp4 format. My laptop would play it, but my desktop would not. No google searches yielded a solution, but one hinted that firefox (v19.0) html5 support is not yet complete, and in fact html5 isn't really there yet in general. Poking around in the source of the error page made it clear that the video was coming in through html5. A further google search got me to This link, which leads to the Youtube html5 trial page, where I found a link at the bottom that offered to remove me from the "html5" trial. I vaguely remember joining this effort over a year ago when I was playing with html5 on my own web site. Clicking on this solved the problem. The reason I did not have the problem on the laptop is because I was not logged in, so youtube did not use html5.