You can not not share a You Tube inside an Adobe Connect meeting room and have consistently, reliable results. 

Two options are:

  1. You can use the Web Links pod to force attendees’ browsers to open a designated URL. 
    Here's how: http://help.adobe.com/en_US/connect/9.0/using/WS11d1def534ea1be08a52b610b38bfaa95-7f4c.html

  2. You will need to convert the YouTube to an MP4, then upload the MP4 file to a Share pod and play the file.

    To successfully convert a YouTube video and a MP4 so that it can be played AND recorded inside an Adobe Connect Meeting Room, go to youtubedownloader.com, Install the Free YouTube Downloader program.