Why are some spawn points not working on Halo 3?

[HamBro64]

I have a Slayer Map where two people tries to snipe each other across a barrier, so I need to have certain people spawning in certain areas, so that way if they die, they cant sneak behind them and assassinate the other person. My problem is that when someone dies they always spawn on one side and never on the other, no matter who dies. Can someone help me?
I have already set Attackers on one side and Defenders on the other side and made sure that there wasnt any Neutral.

 

[dan]

go to monitor form and hit x then select spawning and change the team from neutral to like team 1 and 2