I've the same problem, mysql 4 and jbportal 2.4cr2 boundled.
Any help, thanks in adv,
New users can be created from the home page of the portal. When you are logged out, in the User Portlet, click the "create one" link. The portal is set up so that users can create their own logins (rather than an administrator pre-configuring user ids).
The problem with role creation should now be fixed in CVS. Thanks for the report.