User creation gets progressively slower

When automatic user creation is enabled this module will create a user with username= nick + 'N' where nick is the provided sreg nick and 'N' is the lowest integer that results in an available username.

When sreg nicks aren't returned by the OP it uses 'openiduser' as the nick for every created account, in which case each new account will result in one more DB access. By the time you reach 100 or so users you could be in trouble.

A better approach if no sreg nick is returned by the OP would be to pick a username based on the emailaddress (if that was provided) or to generate a random username.