Index: views/votingapi_views_handler_relationship.inc
===================================================================
--- views/votingapi_views_handler_relationship.inc	(revision 22)
+++ views/votingapi_views_handler_relationship.inc	(working copy)
@@ -190,7 +190,7 @@
             'value' => $value,
             'numeric' => FALSE
           );
-          $alias .= '_'. $value;
+          $alias .= '_'. preg_replace('/[^a-z0-9]/i', '_', $value);
         }
       }
     }