Index: wp-includes/rss.php
===================================================================
--- wp-includes/rss.php	(revision 19456)
+++ wp-includes/rss.php	(working copy)
@@ -101,7 +101,7 @@
 		// check for a namespace, and split if found
 		$ns	= false;
 		if ( strpos( $element, ':' ) ) {
-			list($ns, $el) = split( ':', $element, 2);
+			list($ns, $el) = explode( ':', $element, 2);
 		}
 		if ( $ns and $ns != 'rdf' ) {
 			$this->current_namespace = $ns;