Posts appearing backwards, the newest first! WTF!?!

This is the second time this happens on my forum.

Out of the blue, the posts on a random thread start displaying backward. The very first one at the bottom and the newest on top. Please take a look at this situation in here:

http://theliberboards.heavenforum.org/fiction-f1/how-do-you-picture-your-favorite-ficiton-characters-t45.htm

I noted that if I move the thread to another area, it displays correctly, but I soon as I put it back where it belongs, it starts displaying in reverse again!!!!

It's rather annoying for the posters and embarrassing as an Admin I checked the preferences and there's none to specifically make the newest posts display first... like in VBulletin for example.

What is going on? Is it a bug or something? How can I fix it?

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EDIT.

In the same area, "Fiction", another thread just did this... what is it!!!!!

http://theliberboards.heavenforum.org/fiction-f1/is-it-me-or-t10.htm

OK I think I fixed it.... BUT!

I had to move all the posts to another forum, then delete the original forum and create another one with a different name (just in case) and then move all the posts to this new forum again...

I wouldn't recommend it. It worked and it took me a little bit because I don't have a gazillion threads. but what happens when I do? I can't move the stuff one by one, can I?

Is there a way of moving a bunch of posts to another forum massively?

And what's your take on the original problem anyways? It's rather weird and unpleasant.

Go to admin panel=>Forum=>Management=>Categories and forums and click on the forum that you have this problem. Then look for this option "Sort the posts of a topic by" and choose "Post's date (most oldest first)".

Luky,

Thanks for the always helpful and precise advice

I'll do as you explain if I ever get this error again. You got any idea why this happens out of the blue like that? Just curious.

Cheers