Index: wp-includes/post.php
===================================================================
--- wp-includes/post.php	(revision 22599)
+++ wp-includes/post.php	(working copy)
@@ -581,6 +581,12 @@
 			wp_cache_add( $_post->ID, $_post, 'posts' );
 		}
 
+		// Sanitize the post if it has not been satized.
+		if ( empty( $_post->filter ) ) {
+			$_post = sanitize_post( $_post, 'raw' );
+			wp_cache_set( $_post->ID, $_post, 'posts' );
+		}
+
 		return new WP_Post( $_post );
 	}