Believe it or not, it's by design. Although it seems to be a gratuitous change of a basic ui element; I didn't figure it out for over a year (never occurred to me to right click on the scrollbar, and so I just used uvnc via wine as a client).
The current behaviour is that left clicking on a scrollbar will move the bar down or to the right (depending on the orientation), regardless of where you click in the scrollbar. Right clicking has the opposite effect. Dragging has no effect, and there's no mechanism to move the scrollbars via the keyboard. Expected behaviour would be to use standard scrollbars, where you can drag the bar; left-clicking above or below the bar will move the bar one screen-size up or down, and right-clicking would have no effect. Also, some mechanism should be provided to scroll via the keyboard, although this may be non-trivial for this application. -- Scrollbars poorly implemented in "VNC Viewer" Terminal Server https://launchpad.net/bugs/51741 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs