categories list are on the main manu

hello,
I have a strange problem, all the categories are on the top of the register user, and i tried without a success to make it strait.
open this link to understand what i mean exactly:

www.livegol.org/store/index.php?option=c...irtuemart&Itemid=149
can you advice me what to do for fix it?..

It looks like you missed to close some tag in content. Try w3 validator:
validator.w3.org/

thank you for your advise..

which file i need to check in the validator?
have you ever meet this kind of problem in the appearing of categories?

Not file, content in articles, content in custom html modules. But if you did not used HTML mode editing WYSIWYG editor should not create such conflicts itself.