The ideal way to do this would be to include a "canCollide" local variable for actors. You would also need to switch off the infinite option and copy out the clones yourself.
(This is where the local variable bug will bite again.)
In the mean time, clone out and position the actors yourself and test for
actor name to determine if it requires special collision scripting.
ie
Collision Event
If (actor.name == "wall")
{
// do stuff...
}
Development Note:
It might be nice to have collision available for infinite actors. This way you could make infinite ground or vertical walls that can activate a collide event.