Membership types and registration modification module shutting down under high traffic and maybe a fix for it.

The module shuts down under high traffic on my site, and starts acting weird. I have shared hosting and thus litte memory etc. I chased this problem down to module's use of session variables for people that are not logged in, which somehow is messed up during hig load due to Drupals cache function. That's my hunch. Anyways I rewrote the module a bit ugly but it doesn't use session variables for the registration process, it also moved the role choosing to the password and username form it is thus only one step for registering.

Now my fix is ugly but I think it works, and you might wanna improve on it.