Does it have the proper prefix for your game mode? Example: "DM-Mapname". If it doesn't have a proper prefix, it doesn't know what game mode to use.
If you have a hard time placing player starts, I find they are easier to place on BSP rather than static meshes. I haven't used terrain in a while. Also, a good geometry build is useful as well, just so everything is built properly (mainly BSP, I am not sure how it effects terrain).