UV Mapping - split textures

[some_yahoo]

I have a single mesh that I have assigned multiple materials to the faces.
For instance: Interior_Walls, Floor, Exterior, Roof, Ceiling, Windows.

When I UV Map, I select by material, and unfold each material type into it's own Map.

Unfortunately, What the Wings does is map the different maps onto the same texture.

i.e. myObject_auv or something like that. I want it to give me Interior_Walls_auv, Floor_auv, etc, and not map all the different textures to the same UV map.

Possible?