OK, I think youtube stopped allowing iframe for the channels. Too many people asking for channels only to be emedded by authorized sites maybe?

You have to create a separate player now so only authorized people can make it look like a page. To do this, sign into your youtube, then go to: http://www.youtube.com/my_players

Then create the player you want (you will probably have to create a new playlist to capture all the videos) and then get the embed code and put it in a html box under the source.

For updating videos, just remember to update your playlist when you upload a new video.