Problem with sub-forums

[Desesperao]

Hi everyone,

Let me explain... It?s a bit difficult and I don't know if I'm going to be able to do it well in English.

First of all I have created a category. Inside it I?ve created a sub-forum and, inside of this one, other one. Now, the problem is that the threads are showed in duplicate.

Here is an example: http://www.foromotos.com/forumdisplay.php?f=31

The problem is that the first and the second sub-forums are showed in the category, instead of showing only the first.

Is there some possibility of hiding the second subforum inside the first one?

Thanks