Just be sure to insert your code by clicking the HTML editor button (in TinyMCE and JCE) and placing it there. Click save and Voila! Great plugin, great support, and it's free!
That is NOT a ringing endorsement from the joomla developers. It would literally be faster to create a new site in 2.5, and copy and paste over all our information from the old site. The only positive thing I can say about it is that it's smart enough to put everything in a separate directory so you don't end up with a corrupted site.