I open the cover manager ("Open Cover's Manager"). In the dialog I choose "Add a new Cover". Now I click my picture (pic.jpg). The cover is now imported and I close the manager. Now I use the arrow key down and scroll to the next movie without a cover (some movies down). If I found one without a cover I'm searching the internet for a cover and want to save it over the existing picture (pic.jpg). But I'm not able to overwrite it, as XMM 5.2.5 keeps an open handle to the file. So I have to scroll around in the movie list till the handle is closed.
This doesn't happen everytime, but it's very annoying