single display
 

This is a new installation under Mavericks, never had a displaylink
device before. Using the 2.1 driver beta.

When activated, the same video is driven to both the main display
and to the DisplayLink display. It's as though there is only one
screen object. The "displays" control panel shows only a single
display, no secondary screen.

Effectively, the displaylink is a slaved display rather than
an independent screen. I have not been offered any
option to treat it as independent.

click over to the "arrangement" tab and uncheck "mirror displays"

(sound of hand hitting forehead)
thanks.

no worries :)