Index: wp-includes/query.php
===================================================================
--- wp-includes/query.php	(revision 17751)
+++ wp-includes/query.php	(working copy)
@@ -2231,10 +2231,6 @@
 			}
 		}
 
-		if ( !empty( $this->tax_query->queries ) || !empty( $q['meta_key'] ) ) {
-			$groupby = "{$wpdb->posts}.ID";
-		}
-
 		// Author/user stuff
 
 		if ( empty($q['author']) || ($q['author'] == '0') ) {
@@ -2480,6 +2476,10 @@
 			$where .= $clauses['where'];
 		}
 
+		if ( !empty( $this->tax_query->queries ) || !empty( $q['meta_query'] ) ) {
+			$groupby = "{$wpdb->posts}.ID";
+		}
+
 		// Apply filters on where and join prior to paging so that any
 		// manipulations to them are reflected in the paging by day queries.
 		if ( !$q['suppress_filters'] ) {