Thanks for reporting the problem. I think what happened with the lost thread is that some author deleted his post, causing the branch under the deleted to get thrown out of the forum.
The lost thread is here:
http://n2.nabble.com/Re%3A-Varifr%C3%A5n-%C3%A4r-bilden--Kom-med-i-bildspelet%21-tp1595058p1595058.htmlTo fix it, you can simply ask the author of this post
http://n2.nabble.com/Re%3A-Varifr%C3%A5n-%C3%A4r-bilden--Kom-med-i-bildspelet%21-tp1595058p1595058.html to click "More->Move thread to..." to move this thread back into the forum or to be under a certain post in your original thread. You need to find the permalink of your target forum or post, then ask the author to invoke the command to move the thread back.
This may be a bit unusual, but we designed it this way intentionally.
When an author deletes his post, the discussions under it probably won't make much sense anyways, so we just remove the entire branch under the deleted post. They still exist, but they just become orphaned posts. Is this a bad design for the situation you just experienced?