I've noticed that there seems to be a selection/highlight race condition that happens sometimes when working in the file browser with "Automatically scan all new files" enabled.

If I drop an album directory (which automatically starts scanning) from the left pane browser into the middle pane, and then immediately expand/contract another directory lower in the file browser list before any of the files being scanned has a chance to be identified, then sometimes all the items between the folder I dropped into the center pane and the folder I clicked on the triangle to expand/contract (inclusive) become selected/highlighted even though I did nothing to select multiple items.