Index: wp-includes/author-template.php
===================================================================
--- wp-includes/author-template.php	(revision 12085)
+++ wp-includes/author-template.php	(working copy)
@@ -328,7 +328,7 @@
 
 		if ( !($posts == 0 && $hide_empty) && 'list' == $style )
 			$return .= $link . '</li>';
-		else if ( ! $hide_empty )
+		else if ( !($posts == 0 && $hide_empty) || ! $hide_empty )
 			$return .= $link . ', ';
 	}