Strangest thing - problem is solved but I'm not quite sure how.
The problem occurs on my HP notebook when I use it, using remote desktop from my home PC (then I can use dual large screen configuration). When I work on the notebook itself, the problem does not occur, neither on my home PC itself.
Because the problem was back suddenly I tried to think of what changed recently. Microsoft updates is one of the things constantly changing the system. So I uninstalled the most recent updates on my notebook, but no luck. Then I realized it may be the host/remote
situation causing this, so I uninstalled first the most recent Windows update (KB2820331) on my home PC. From then on, the problem was gone!
Days later, KB2820331 was installed automatically again but the problem did not return. That is why I'm still not sure what caused the temporary re-occurence of the problem.