Index: administrator/components/com_comprofiler/plugin.class.php
===================================================================
--- administrator/components/com_comprofiler/plugin.class.php	(revision 831)
+++ administrator/components/com_comprofiler/plugin.class.php	(working copy)
@@ -2379,7 +2379,10 @@
 
 		// Recurse:
 		foreach ( $this->children() as $child ) {
-			$subFormulas[]					=	$child->reduceSqlFormula( $tableReferences, $joinsSQL );
+			$subForm						=	$child->reduceSqlFormula( $tableReferences, $joinsSQL );
+			if ( $subForm != '' ) {
+				$subFormulas[]				=	$subForm;
+			}
 		}
 
 		switch ( $this->name() ) {