IP change after successful login

I notice that my users get a second IP address after they login successfully. The IP is coming from the same pool that I give the user when they connect to my wireless network. How do I prevent them from getting a second IP.

Should I simply remove the pool from user profile in hotspot?

Thanks,
Dave

I solved this by removing the address pool from server profile and user profile.

http://forum.mikrotik.com/t/second-ip-after-login/45229/1