Are you perhaps working in a template with frames threaded across spreads that skip pages? If so, are you maybe hitting the Number Pad Enter key?
Not really, the jumping occurs often when only clicking the mouse, far away from the keyboard.
Is this a "recycled" file that's been resaved many times? Try a trip through .idml. See Remove minor corruption by exporting
And what mouse are you using? Can't remember which one, but either the Mighty Mouse or the Magic Mouse was prone to all sorts of strangeness in ID.
Thanks a lot! The recycling seems to be the problem, as you suggested. I tried out to create a completely new documnt and so far and in a small scale I tried to click and Enter things - and no jumps were seen.
Thanks, have a nice day, Peter.