Unity re-ordering triangle indexes??

I've imported a mesh from 3d Studio Max.

The mesh imports with the correct number of vertices and triangles.

However, the triangle indexes of the imported mesh are different than the ones in my 3d app. It's like Unity re-orders the triangles during import? This is very frustrating because I need to coordinate some data between unity and 3dsmax that is triangle-index dependent. Everything breaks when triangle n in Unity is not the same triangle as triangle n in 3dsmax.

Has anyone encountered this before? Is there a fix/workaround?

Do you have any optimizations turned on when importing?