Sprites are not drawn

[Codewalker]

I use NGUI to make some notification windows in my game. I use the 3D-GUI and have several panels attached, that are centered and displayed via NGUITools.SetActive . To make it more fancy, I use an animation of the Scaling.
For most notifications, it works. But sometimes, I only get to see my label with text text, but no other sprite (background, etc.). In the Scene View I can see the bounding boxes, but nothing is painted. Where is my mistake?

[ArenMook]

You can't have a starting scale of 0. It's invalid. You need to use a low but valid value instead, such as 0.01.