Originally Posted by
Globaliser
It looks to me like this may have been a side-effect of an edit to the thread title. If you look at the bits of thread title that are reproduced in the links, you'll see that they are slightly different.
Actually the text in the link makes no difference, it's the numbers. The text is just there for search engine optimisation. This means links usually work when thread titles change. Look at these examples (hover over the links with your mouse to see the URL before clicking on it, the site will automatically update to the latest URL when you visit the page):
http://www.flyertalk.com/forum/briti...y-hamster.html
http://www.flyertalk.com/forum/brit-...mond-club-446/
Try it yourself after /forum/ only the numbers matter, you can change any of the text in the URLs and it'll still work.
There's no reason why closing the thread or changing the title would break old links.