Incorrect Coordinates Palette when working in 3D window

[Anonymous]

Hi everyone
Just wondering if anyone has experienced this? I get the feeling there must be a quick fix for this.

In the 3d window, my coordinates palette always shows coordinates and angles as absolute values. The toggle button with the delta symbol (∆) in the coordinates palette seems to have no effect. Is there something I can do to reset this so I can measure between two points and se the relative values ?

Thanks