also a big problem with tf2 is a pyro or demoman or preatty much any class can run to the other teams spwn and just camp their and not let them leave. Mainly on the levels which have only one exit route).
This is a plugin which will allow given seconds (i vote for like 3 seconds) to let people leave their spwn,, and if someone is their camping it, they cant just keep killing you over and over.
Spwn plugin http://forums.alliedmods.net/showthread.php?t=69290