Index: meta-boxes.php
===================================================================
--- meta-boxes.php	(revision 38182)
+++ meta-boxes.php	(working copy)
@@ -630,7 +630,7 @@
 <?php
 $metadata = has_meta($post->ID);
 foreach ( $metadata as $key => $value ) {
-	if ( is_protected_meta( $metadata[ $key ][ 'meta_key' ], 'post' ) || ! current_user_can( 'edit_post_meta', $post->ID, $metadata[ $key ][ 'meta_key' ] ) )
+	if ( is_protected_meta( $metadata[ $key ][ 'meta_key' ], 'post' ) || ( is_serialized( $metadata[ $key ][ 'meta_value' ] ) && ! is_serialized_string( $metadata[ $key ][ 'meta_value' ] ) ) || ! current_user_can( 'edit_post_meta', $post->ID, $metadata[ $key ][ 'meta_key' ] ) )
 		unset( $metadata[ $key ] );
 }
 list_meta( $metadata );