I've had a similar behavior when I generate a track for a few bars. Say I hi-lite one track bars 6 thru 20 and generate. I listen to the track and want to scroll back to bar 6 and try again with a different instrument. I click the left scroll bar arrow once. But instead of the screen scrolling to the left it jumps to the right, to say maybe bar 32 or so. Nowhere near the spot I stopped the playing. It jumps so far to the right with that one mouse click that I have to click the left arrow again quite a few times to get back where I was. I'm used to it now. And it doesn't happen consistently. But it is a pain. I haven't really taken notice of it since I updated to version 6. SO maybe it's fixed. I'll have to keep watch.