To reproduce:
1. Create new object.
2. Add cloth component to it.
3. Press on a "gear" on cloth component. "Move down" can be pressed, even though Cloth is at the very bottom

Expected result: "Move down" is grayed out and can not be pressed.
Actual result: "Move down" can be pressed.

Reproducible: 2017.3.0a7
Not reproducible: 2017.2.0b11, 2017.3.0a6

Notes:
If Game object has Cloth component, then any component which is at the bottom can be "Moved down" one more time. (which does nothing, since component was already at the bottom)