I am trying to get a youtube video to show up on a Joomla 1.5.22 site.

When I put the tag: {youtube}s82DnROUj2A{/youtube}  into a Joomla 2.5.2 it works famously.  (www.57years.com/)
When I put the same tag into the Joomla 1.5.22 site, it just displays the tag rather than a player.

Please help.

AllVideos has two version: one for joomla 1.5 and one for 2.5.
Make sure you have selected the appropriate one.
In addition, upgrade your joomla 1.5.22 to 1.5.26 please.