I had a Facebook game, made with Unity utilizing NGUI. When the game loaded up for the first time, Facebook's dialog showed asking for permissions. To do this, the Unity container of the game is minimized.
The problem is when the game regained focus, some labels of the game were HUGE (And I mean huge, I could tell it was a label due to the color showing up, which was all I could see).
This happened everytime the game resized.