PostgreSQL keepalives help

Hy,

I have a system working with the client-server structure and PostgreSQL 8.4.
My problem is that if a client who is editing a record and lose his connection to the server,the TCPIP connection is still considered! So, the record stay allocated for the client in my database.
I need the records are free for edit, in few minutes. Therefore I set the KEEPALIVE configuration in my "postgresql.conf":

tcp_keepalives_idle = 60 # TCP_KEEPIDLE, in seconds;
tcp_keepalives_interval = 60 # TCP_KEEPINTVL, in seconds;
tcp_keepalives_count TCP_KEEPCNT = 5 #;

After making these settings and restart the server, the system continues to function the same way: Just breaks the connection TCPIP after two hours and then deallocates the records in PostgreSQL. I need a efficient and safe way for the PostgreSQL understand that is to break these connections as configured! I need help, urgent!

Thanks,

Kananda S Silveira - Desenvolvedora .NET / Analista de Banco de Dados
STEP SOFTWARE Tecnologia e Projetos LTDA
kananda(at)stepsoftware(dot)com(dot)br<mailto:kananda(at)stepsoftware(dot)com(dot)br> / +55(48)8417-8121