This bug has been around since the Alpha, but it just irked me again so I'm finally reporting it.
If you bring up one the quick panel (ctrl/cmd+p) and it has enough items that it needs to scroll, and you use the arrow keys to scroll to the bottom of the list, it behaves as expected. But if you then try to scroll back up, the selected item is "locked" to the bottom of the box, and it scrolls you up with each "up" keypress, hiding the item below it. It should only do this when you reach the top of the visible region.
The command palette works as it should, but the quick panel doesn't.