Looking at http://e621.net/post just now, I noticed that the first one on the page was #51283 and the last one was #51263 even though it should have been #51264.
Checking the thumbnails on the page, I found that there was no link to #51276. The thumbnail for that one simply didn't show. Even though when I try e621.net/post/show/51276 it loads just fine
This happens in the latest available Opera, Firefox and Internet Explorer and I always view e621 with my ad blocker disabled (not just set to not block e621).
Why are some thumbnails not showing for me and how can
Updated by user 7