Menu link to create a VM account

[django29]

Hi

I put a link in the mainmenu to the "Account maintenance" page of VM, and it looks perfect, but when we enter the customer informations, and create an account, the form just disappears and is replaced by a page of links on images : categories, featured products, new products ....
No message to confirm the registration, no email sent , and nobody registered ...

Where can I change the parameters of this form, and make it work   : welcome message, thanks message, URL to open after validation ... ?

THE website : http://www.landerne-primeurs.com/inscription

Joomla 2.5.27 + VM 2.0.20b