Normal Map, Tangent Binormal on Mirrored Objects

[farshizzo]

How are you mirroring the UVs in Max? Are you using the Coordinates rollout in the material properties or are you mirroring the actual coordinates through the Edit UVWs dialog of the mesh?

The tangent/binormal calculation is based on the raw UV values, and does not take the texture tiling mode into account. So you should try to use the second method if you are not already doing so.