Hi Andrew: the fix that I used is as follows:
Note: The way I have things setup is that my webpage is in the root of the hosting and called products.php (this file uses framework builder to use a plg_products.php file thats located in plugins/functions (so 2 folder deep).
the facebook code will be in the plugin file (plg_products.php) since this file is the one that will display individual products using the filtered recordset.
the facebook code I used is automatically generated by WebAssist extension, except for the action="" segment I manually changed it as follows:
...depending on how deep your folder structure is..mine is 2 folder deep so i used ../../
I hope that helps.