I think you're misunderstanding what I'm talking about.
When you click, then yes, it should jump to the code section, not "scroll" to it. (I believe this is what you thought I was referring to?)
What I'm actually referring to, and this can be reproduced everytime so go ahead and open both ST2 and ST3 and give it a try, is when you click and hold, you should be able to drag the window. In ST2, you can drag the preview window up and down. In ST3 you can't.
Edit: to clarify further: in ST3 I can click and hold the actual window and drag up and down, but if I click in a section of code that the preview window isn't on currently and hold and try to drag, it doesn't.