Steps to reproduce:

1. Open attached project
2. Open scene "Mecanim_Update_Test_Scene"
3. Investigate "Constructor_Enabled" and "Contructor_Disabled" game objects in hierarchy
4. Notice that "Constructor_Disabled" has Animator but it's disabled. Also, both of these objects have Animator.speed set to 0.3
5. Run scene and notice that animation of object with disabled Animator plays much slower
6. Stop scene, set "Anim speed" of both objects to 1
7. Run scene and notice that now animation plays with the same speed
8. Stop scene again, set "Anim speed" of both objects to 2
9. Run scene and notice that this time animation of object with disabled Animator plays faster compared to other object