Disobedient Graphic

Hello,

I’m having a bit of trouble with a particular graphic in my flash animation.
What I have, is a simple graphic, which consists of 9 keyframes to play an animation.
On the main timeline, I tell the graphic to move about a bit with tweens using the “Single Frame” option to keep it on frame 1. Then at a certain point, I want to change it to “Play once” so it will play its animation.
The problem is, it seems to be stuck on “single frame” and will not let me change it anywhere but the first frame.
I’ve tried setting the very same thing up in a different scene, and it works as I want.
Would anyone know what’s causing this behaviour?