Yes I've managed to replicate this, although mine seems to jump to the end rather than the start. For me it only occurs if you're scrolling by clicking and dragging the scroll bar, using the mouse wheel and slipping onto the taskbar has no effect.

I think this happens with other programs normally though. For example, put a browser to the left half of the screen with a window open that has a scroll bar, and (using the mouse to drag the scroll bar) move up and down but slip off the browser to the right and by default it will go back to the top of the page.

Cheers,