textures/materials break when using groups

Hey

I have a nice model of a house with colour, normal and ao maps. I want to link this model into a city scene I’m building. So to make selection of house and all it components easier I associate them all with one group.

But when I link the house model/group to my city scene the textures on the house mess up. Normal maps corrupt and and some house components are drawn with the wrong texture.

Any ideas?

thanks in advance

Have you tried using an empty as the parent?

Yes tried using an empty as a parent.

Now is it a fault in my scene or should I report a bug?