Shadows showing up through geo in forward rendering with directional light

Title says it all pretty much- For example, if I'm on the first floor of a building, and you're on the second floor, I can see your shadow being cast on the floor in front of me, and on the ceiling above me. The behavior is very much line a projector- but it's the dynamic cast shadow from a directional light.

Normally I work in the deferred pipeline with dual lightmaps, but for this project I'm using forward rendering with a single lightmap. Anybody have any ideas?

This is happening in Unity 4, I don't have 3.x installed anymore so I'm unable to test it to see if it's just a 'new' bug or not...