deleted mates and other motion questions

1. We've had three or four instances where a mate was deleted by SW in a motion study (animation.) I've come to suspect that selecting "no" in the "update initial animation state" window (see image) may cause mates to be deleted. Can anyone verify that?

2. Is there any way to recover a deleted mate in a motion study (animation)?

3. When I edit a mate dimension in a motion study (animation), the feature tree rearranges itself such that I lose my place. Some features collapse, or the tree shifts from one mate location to another. I'd prefer the thing didn't change so that I can work without interuption. Does anyone know if there a setting to stop this behavior?

Thanks

SolidworksMotion Studies