how can i use my license in David 1.4 or must i buy new license

Can u explain me how the fps indicator works? I use 30 fps for scanning, but the indicator sometimes shows less then 20 fps?
Now some questions about the 3d window:
How can i choose another camera? Only cameraview on button 1 works, all other buttons show a black window!
Can u explain me the "Draw partition circle for motion identification"?
Why couldn't i switch the grabbed texture on/off, after "Fuse" the meshes?
Ok that was it first times for now

nice day @ all
Tobias