Problem with the user administrator

[jorgepracticum]

Hi
I'm using virtuemart 3.0.11 and Joomla 3.4.4 and when I'm trying to grant permissions to another user to administrate the shop and edit the component from the frontend, it change my superuser data. I mean, i fill the fields of the backend form to the shopper information and I write some username, and the component edit my superuser data with the data that i just have given...
How can i grant permissions to administrate the shop to another user?? I don't want that the superuser administrate de shop
Regards

Edit:
I'm following this example http://docs.virtuemart.net/manual/general-concepts/44-multivendor/197-example-to-setup-acl.html but when I access to the ACL manager of VirtueMart and I select the permissions that I want and press "Save", nothing happend, no permissions is saved