Depth buffer bug? Goes away with maximize on Play

I am using Unity 4.0.1. I have to as I am using plugin that doesn't support higher versions.

When I first hit play some of the meshes in game window overlap the wrong way when camera rotates around them - those in front appear back, far side of the mesh in front etc.... Once I hit play with maximize on play and then back to normal meshes sort OK from that point on but built application still has the same problem.

This only effects perspective projection. Ortographic is OK.

Is this a bug in Unity? If so... How can I emulate this maximize on play routine in deployed Android application?