Recommend email error 500

I had recommend running on a previous install of Joomla 1.5 and it all worked great.

I recently installed a fresh version of Joomla 1.5 on my new server and uploaded Recommend to it, set all the settings exactly the same, and now I get a Error 500 Internal Server Error message after clicking the "submit" button.

I don't know if I am forgetting to install something in the new server or what. I have Legacy 1.0 turned on because some other plugins/modules I use require it and all of my server settings for sendmail are exactly the same as before. The only thing I did was change the server machine within my own home network and I installed everything fresh from scratch.

Any ideas on maybe something I missed or have not installed yet that will help this run? I have been through the old server and new server configs repeatedly.

Another thing I might point out is that I am using Linux and I may not have a required library or program installed on it that I did on the previous server, maybe a php library or something?

Any and all help is much appreciated. All other mail functions for Joomla work, just not for Recommend.

It has not been tested on Joomla 1.5 yet, you will have to wait on this one.