Try contacting Joey Doyle at jdoyle@aldine.k12.tx.us. He is the program coordinator for the conference and should be able to tell you which sessions still have openings. Another possible source of information is Judy Shimp - her address is Judydda@aol.com.
I hope you will please plan to attend Lee Smith's slide talk on Saturday. It is free and unlimited as to number. Good luck!