Thanks Inigo for your reply. Theme my login is actually a plugin not a theme. It allows to customise your own secure login and registration pages according to your theme. It also redirect users upon log in and log out based upon their role.
This does nor apply when customers make a purchase. When they order, the registration/login go through the TheCartPress settings and page.
It has been fine before but with the latest Theme my login plugin there is
double up password fields showing on The Cartpress login/registration page. (So the fields are shown 4 times)
Hope that helps to pinpoint the problem.