If you wish to keep the CTRL key pressed and scroll up or down a grid list, just use the mouse on the scroll bar on the RH side of the grid.
To zoom you need to press CTRL and +/-.
If you press the CTRL key and try to use the up/down arrow keys to scroll it will increase/decrease the flag status of the currently selected image.
Thank you for the reply. But it does not solve the problem at all - when the grid contains large number of photographs, scrolling with the bar skips is very jerky. There is no way of telling if some photographs were missed, so it is not practical at all.
Is there a way to switch the zoom function off?
I don't think so but on my keyboard the zoom functions are"
I don't see where any of those keys and combinations would affect scrolling?