I have installed the PayPal plugin on my website.

I have began testing ordering pictures using basic users I have created: Matt Walters, and Bill Smith.

The problem I have is that I log into my website as Bill Smith and order pictures A and B and can see them on my PayPal cart.

I log out of the website and log in as Matt Walters. I order pictures A and C.

When I view the PayPal cart again, it has kept Bill Smith's order and added Matt Walter's order so the total order has

Picture  QTY
    A         2
    B         1
    C        1

This makes me worried that if more than one customer is logged in to the website and tries to order a picture, they will get more than what they wanted.

Is there a way to separate the cart by username?