Index: branches/5.2.x/core/units/helpers/user_helper.php
===================================================================
--- branches/5.2.x/core/units/helpers/user_helper.php
+++ branches/5.2.x/core/units/helpers/user_helper.php
@@ -270,7 +270,7 @@
 			if ( !isset($cache) ) {
 				$sql = 'SELECT IPRestrictions, GroupId
 						FROM ' . TABLE_PREFIX . 'UserGroups
-						WHERE IPRestrictions IS NOT NULL';
+						WHERE COALESCE(IPRestrictions, "") <> ""';
 				$cache = $this->Conn->GetCol($sql, 'GroupId');
 			}