after registration error 404 page

I have an interesting problem:

1. When I trying to register a new user in this page (/index.php/component/users/?view=registration) then displaying 404 error in this page (index.php/component/users/)

2. But if I manualy add new user in joomla controlpanel (users => user manager => add new user), then
I can login in my homepage using login system...

How to fox this registration problem?

Look up to my user configuration:

Hello,

You should delete com_user in templates/ot_boutiquebox/html folder

Regards

I don't have com_user folder in templates/ot_boutiquebox/html folder, but
I have in this folder com_users folder.
I deleted it, and tried register a new user, but nothing changed - still error 404 page is displaying....

Other solutions?

Can you send me your administrator account to email: trungdt(at)omegatheme.com ? so i can check it ?

Regards