Index: wp-includes/query.php
===================================================================
--- wp-includes/query.php	(revision 17521)
+++ wp-includes/query.php	(working copy)
@@ -2221,7 +2221,7 @@
 				$eq = '!=';
 				$andor = 'AND';
 				$q['author'] = explode('-', $q['author']);
-				$q['author'] = (string)absint($q['author'][1]);
+				$q['author'] = implode('',$q['author']);
 			} else {
 				$eq = '=';
 				$andor = 'OR';