Thanks for the reply. I am not sure I explained it properly going by your reply.
1. Customer goes to checkout but gets autoredirected to login page if not logged in.
2. On login page if user logs in they go to the checkout page (not user profile)
3. If they havent got a login using the SecurityAssist behaviour show if not logged in they get a link to register.
4. After they register they get auto-redirected to login page - its here the problem they get directed to the the user profile is there a way to hold the ?checkout=1 to redirect them to the checkout if thats where they originally started?
I hope thats clearer.