Unity Physics Collision fine in Editor but not working in Standalone and Webplayer?

As stated in the title collisions in the editor work fine but fail to work the same in Standalone and Webplayer builds (Unity 4 Free).

This is very odd as the collisions that are happening in the Standalone and Webplayer builds should not occur based on the physics layer settings.

I the game I have people, zombies and troops. So a person layer and a zombie layer, and units have to be able to detect each other so I added a sensor radar on it’s own layer and a sensed collider on it’s own layer.

This allows all units to detect each other regardless of their layer types. The sensors have big ranges and the sensed colliders are small sphere colliders nested in the Units.

And only sensors and sensed can detect each other in the physics settings. But in the Zombie/People OnCollisionEnter routine in the webplayer and standalone builds I get hit’s from sensed colliders. This is very odd as it does not happen in the editor and should not happen due to the physics settings.

What makes this even more peculiar is that this was working fine in a previous build when I was using the Pro Trial license but as that has expired I have reverted to the Free license??

Is there a difference in the Physics and Collision detection systems between Pro and Free or is this a bug?

Raised as bug 538322.

OK I removed the sensed sub collider and moved the sensor detection back to the higher level Person, Zombie layer and it has fixed the problem.

No idea why a sub collider on a layer that does not interact with other layers was responding as though it did, very strange!