Material Browser -view won't scroll up or down with arrow keys

How to reproduce:

1. Add items to MATERIALS and/or to TEXTURES -field in the Material Browser -view, so that you can scroll up and down.
2. Navigate the items with the arrow keys. Try to navigate the items in the bottom or in the top, that are not in the view.

The horizontal scroll in the Material Browser should follow the blue rectangle, that user operates with the arrow keys, but it doesn't.