Bug when hovering over a square button and when minimizing and maximizing window

[Cabido]

I've noticed, while making an interface mod, that, sometimes, the graphical change, when hovering over a square button, doesn't display and, sometimes, when leaving the button, it sticks.

There is also a problem with the intro/scenario selection screen: if we minimize the window and maximize it again, the screen doesn't shift to the center and all the buttons coordinates get messed up.