#940 Dragging Animations when collapsed causes them to get remove

[mukuste]

Steps to reproduce:

1. Create a new Direct-X game.
2. Insert a sprite.
3. Go to the sprite's animator bar and add a new animation.
4. Collapse both animations in the bar by clicking the minus signs next to them.
5. Drag the "Default" animation below "Animation 1".

An error message pops up with a message (curiously, it is in German on this laptop with a German version of Vista) translating roughly to "An invalid argument was detected."

6. Deselect the sprite and select it again, and one of the animations will have vanished.