I don't quite follow you here... tween position simply tweens some object's position from A to B over desired time. What scrolling are you talking about? What are you trying to scroll? Do you mean "interpolate" instead of "scroll"? Calling PlayForward() will start playing the tween from its starting position to the end. Try a simple scene with a tween on an object (make sure to disable it so it doesn't play automatically), then add a button that will call the tween's PlayForward() function in its OnClick.
Hmmm... I think I didn't describe this right. Put it simply...I want to tween the position from A to B over 1.25 seconds. However, it doesn't tween...it just moves it to the spot when I play the animation. There's no tweening going on. It works in other instances, however, in this one it only works if I ping-pong or loop the animation. Which isn't good. Just not sure why it doesn't move from A to B over time. It only moves from A to B immediately.
Hopefully that makes more sense. I've got moving windows and elements all over my UI, so I know how it works. It just doesn't work in this instance. Wondering what would cause that behavior. Is there a limit to how many objects can be moving at a time?