rexrainbow - Thanks man, I will use the occasion to thank you for all your contributions here; it helps us, newbs, a lot
Okay, it still doesn't work properly. It might be related to my general (mis)understanding of the software but bear with me:
1. My thumb starts at about line 12-13 (instead of line 1 as it is in the example).
2. When I try to drag it it works properly for dragging down but if I try dragging it up it constantly tries to snap back to its original point (line 12-13).
3. If I drag the thumb I can take it outside of the scroll box (although it's "fixed" to only move vertically) and it snaps back to the bottom-most/upper-most point of the scroll bar when I drop it.
Note 1: I believe to have made a carbon copy of the event sheet, I have assigned the necessary Boundary/DragDrop 2 behaviors to "thumb", Scrolling to "Text", and UP/DOWN image points to "bar".
Note 2: The example .capx runs properly on my machine so it's not an issue of platform/input method, etc.