[Not Opus] Folder list jumps up before selection

When I select a folder in a disk, and then go to another folder a bit further down, after a short period (guess 0.5 second) the folder list jumps back up, sending the required folder out of view. I then have to scroll down again.
This happens every time I go to a different disk and is very frustrating.

Whoops, it's not DO's main lister window, but file save dialogs. If I have selected the replace Explorer with DO option, I assume that this is still DO.

File Save dialogs are unrelated to Directory Opus.

Thanks Leo. I'm ashamed for thinking, even for one second that it could be DO.
Now I'm off to a Windows support site - wish me luck.