Try adding debug output at the top and bottom of the rdf.class.php script and see if it actually gets loaded.
You could possibly try and raising the error reporting level in the newsfeedpal script before the rdf class is loaded.
Find this:
<br />// Include the RDF class <br />require_once("rdf.class.php"); <br />
Replace it with this:
<br />// Include the RDF class <br />error_reporting(15); <br />require_once("rdf.class.php"); <br />
Then find this:
<br /> default: $CustomBox1StorageString = $cbstorage; break; <br />} <br />
And add this below:
<br />error_reporting(7); <br />
It will report some notices about undefined values, which is OK. But if you could paste all error messages that would be a help.