Index: wp-includes/pluggable.php
===================================================================
--- wp-includes/pluggable.php	(revision 9725)
+++ wp-includes/pluggable.php	(working copy)
@@ -1522,8 +1522,6 @@
 		$default = "http://www.gravatar.com/avatar/s={$size}";
 	elseif ( empty($email) )
 		$default = "http://www.gravatar.com/avatar/?d=$default&s={$size}";
-	else
-		$default = add_query_arg( 's', $size, $default );
 
 	if ( !empty($email) ) {
 		$out = 'http://www.gravatar.com/avatar/';