If you scale widgets or their parents, then you lose pixel-perfection, resulting in blurry looking UI.
Always keep all widgets leading up to parents at (1, 1, 1), with the sole exception of UIRoot. If you need to scale something, scale the widget itself. Scales don't reset themselves unless you click "Make Pixel-Perfect".
If you absolutely must scale the parent of a widget, do so uniformly. Ie: Scale of (2, 2, 1) is not uniform, but (2, 2, 2) is.