Problem with transformation combination component with 0 degree rotations

I have found a problem when combining transformations and I way wondering if anyone has seen this or has any suggestions.

I am unfolding lots of different folded parts.  I am triangulating the parts and extracting a list of rotational tranformations for each triangular face.  The lists are then combined and each face and the entire part unfolds flat.

I have found though, when the parts are orthagonal and the rotational tranformations are 0 degrees (two adjacent faces that are already coplanar) the transformation combination component freaks out.

I have tried replacing the 0 degree rotation transformations with the identity transformation (is that the correct term?) and that works fine.

Has anyone else seen this?