How to reproduce:

1. Open attached project
2. Open scene unity4TorqueTester.unity
- Scene contains 3 cubes:
- Cube 1 (NormalCube) is not rotated and has its rotation locked on the X and Z axes
- Cube 2 (TiltedCube) is rotated 45 degrees in the Z axis and all of its rotation constraints are turned off
- Cube 3 (YRotCube) is the same as TiltedCube, but it has the X and Z rotation constraints turned on
- All of the cubes also have a Constant Force component with Y Torque set to 3
3. Play the scene
- Note how NormalCube and TiltedCube rotate as they would in Unity4 but YRotCube does not. YRotCube appears to be rotating in Local Space