Well, I just discovered a glitch with thread names. The thread named [][][][][][] or w/e is unable to view both the last comment on it, or any page but the first. Why? Simple. Because the [] symbols cannot show up in the url, so it leaves it blank. There is usually a slash, the thread name, then another slash, but without a legible thread name the two slashes are next to each other. Which is basically why clicking on page two of that thread results in a 404. Proof?
There is a feature of the site code and URL parsing that treats slashes differently. For example, a slash that starts a line ends up having another slash next to it, for reasons I can't figure. Maybe it's to do with a glitch with <br />?