To prevent an application from creating a connection with the same set of socket addresses of a connection that is in a TIME-WAIT state, TCP/IP in Windows Server 2003 Service Pack 1 has implemented a smart TCP port allocation algorithm. When an application requests any available TCP port, TCP/IP first attempts to find an available port that does not correspond to a connection in the TIME-WAIT state. If a port cannot be found, then it picks any available port.
This new behavior makes it much more unlikely that an application will be assigned a TCP port that is in the TIME-WAIT state when connecting to the same destination. You no longer need to modify the TcpTimedWaitDelay registry entry.