I've been noticing a few times now, that sometimes when I click on links to specific threads.. the thread will momentarily load, and then suddenly the page refreshes, and I'm given an error page saying "No thread specified". I know the thread is there, because it loaded, but then it's gone before I have a chance to really get a look at it.
That happens when a post within the thread is deleted and you're trying to visit it. What you can do is to remove the #post### from the last part of the url.