[5.2] Scroll Rect elements disappearing and Slider broken at value "0"

Hi Unity team,

I notice two other visible bug in Unity 5.2 :

First is when you suppress UI element inside a Scroll Rect + 2D Rect mask + Layout combo, some element disappear from the list (they appear again when you move a bit the layout).
I just made a bug in the issue tracker about this.

But I couldn't reproduce the second bug I have : I got a slider, if the slider value is zero, then the brut image used for the slider appear incorrectly (with no color or effect, a bit transparent). See...

[5.2] Scroll Rect elements disappearing and Slider broken at value "0"