The "Insert Video" function does not work for Youtube videos.
OS: 64-bit Linux
OS-specific (uname -a): Linux kxstudio64 2.6.31-12-realtime #21-Ubuntu SMP PREEMPT RT Thu Mar 18 12:21:47 UTC 2010 x86_64 GNU/Linux
Browser: Mozilla Firefox
Browser version: 3.6.9
Relevant browser extensions: Ubuntu Firefox Modifications 0.9rc2, Adblock Plus v. 1.2.2
All other browser extensions: Download Statusbar 0.9.7.1, DownThemAll 1.1.10, Forecastbar Enhanced 0.9.6
Whenever I click on the "Insert Video" icon while focused inside of the "Reply" box, a popup will allow me to insert the Youtube video address. It will, however, not display the video in the resulting post.
I've been able to work around this problem by editing the source directly and inserting the "embed" code from Youtube. This, of course, is not very user-friendly.
(1) clicking the "Insert Video" icon and pasting a Youtube video address there:
(2) clicking the "Source" icon and appropriately editing the HTML code for the post to include the "<object>" code from Youtube: