A few times today I have noticed some weird behavior with the "last post" button. The page loads with the thread title but no posts actually appear.
I think it's been previously reported, but there seems to (still) be a post counting bug. Correct me if I'm wrong but there are 10 posts to a page. I've noticed that sometimes the thread counter says there's 11 posts and adds a second page, but when you click the second page there's actually nothing there. Seems to apply to any thread where is a factor-of-ten-plus-one post count. For example, if a thread had 71 posts, it should have 8 pages with the 8th page consisting of one post. In that scenario I've noticed if I hit page 8, it's blank.
Could be related if people are hitting "last page" and it happens to be one of those threads.
On a completely unrelated note, locked threads are way too pronounced and stick out. You should tone down the pink and make it gray or something so it doesn't grab attention.