maya viewport

ingame ogre screenshot

here is the setup, i intended to use two uvsets, one for the diffuse texture and one for the lightmap wich is baked from mentalray.
first, the setup worked fine but at some point it completely refused to work and all maps are assigned to the first uvset even though the material file clearly says it's assigned to the second uvset.
i'm using Maya7, the latest versions of both the Maya exporter (Maya 7 Exporter v1.2.1) and the Ogre engine (also 1.2.1).
why this problem?