Hm, I would skip that hack for viewthreaded.php... Every message you read is a click. I don't know if you disabled threaded view, but if you didn't, I would stick with the default behavior of the script.
Please mind that it will still cache the view counter, it won't be updated until a post is made.
edit: I just saw the thread on ubbcentral, and it's the same as Rick suggested there. Don't know why it would stop with counting all together, I've tested it, and it works.
Last edited by blaaskaak; 09/18/2008 1:56 AM.