When clicking on the "Show more details" button in the Cover Art pane, the focus is removed from the file listing so that the arrow keys will no longer move the selection bar, even after the popup info window is dismissed.

This slows down navigation when I'm checking album art for a set of albums, as it requires extra mouse navigation to select each album rather than allowing the use of keystrokes (arrow keys) to select the next album before clicking the "Show more details" button.

Steps to reproduce:

1. Load several already tagged albums.
2. Select the first album in the right pane
3. Click show more details, and then press "Esc" to close the popup window
4. See that the "focus" does not return to the right pane, and the arrow keys do not allow moving the right pane album selection unless you click back in that pane.