Since updating to CoursePress to 1.2.2.4 the signup button

Hi,

Since updating to CoursePress to 1.2.2.4 the signup button on a course description page no longer works. It pops up and allows you to enter your name, username, email and password etc, but then doesn't go any further. The user is successfully created but it used to then display their cart ready to check out - now it just leaves a blank white box dispalyed on the screen.