Rapid Board Scrollbar down button missing

In the latest GreenHopper 6.2.1 with the new UI, the scrollbar down button is not visible in the screen and cannot be click. A customer has confirmed that this is happening in different browsers of Chrome 26.0.1410, Firefox 21.0 and IE9. I've confirmed that it is happening in Chrome 26 and Firefox 20.

The scroll down button can't be seen in the Plan mode, Work mode, and Report mode.