Some of our users have told me that sometime they post a message, the message is displayed as posted correctly but the same message disappear if they browse the forum and go back to that thread after some time.
I'm the only one that can delete a message and assuming that I've not deleted it I would like to know what could be the case. Maybe an ajax malfunction or something like that?
I think so. Not sure if related to the cache or something other but surely a browser problem I think. Someone told me that sometimes the message disappeared also using the latest version of a specified browser.
When you reply your post is "injected" into the display; it isn't cached by your browser at this time so effectively only exists on your screen (as far as your browser is concerned).
When you click away and return to the thread again through normal page navigation your browser will check with the server and get a fresh copy of the thread data which will include your post.
However (and this is what I suspect is happening), if you use your "back" button to return to the thread your post will not be there because the browser doesn't have it in its cache and so displays what it does have, and that is what the thread looked like before you posted. This makes it appear like your post is gone!
It can be a bit disconcerting but if you ask your members to press CTRL+F5 next time this happens (to reload the thread from the server) I suspect their posts will magically "appear".
Mind you, I only suspect that is what's happening - if you're experiencing something different then it may need some further investigation.