Not sure if I like the way the firewall is set up on 10.5. One thing is I cannot shut off UDP like I do in Tiger. Haven't researched enough but that statement about OS X will determine whats allowed (in preference-(security or sharing)- advanced). I have mine on the select programs. This sucks as I did not allow safari yet but can surf the net. Not sure if apple has all its programs automatically allowed connections which I do not like. I don't even like apples software phoning home when it wants to.
Randy