I recently bought a Nyko Zoom for Kinect which is a lens attachment that is supposed to enable you to use the Kinect with less room.
When I've attached it, it does zoom out more as advertised but the Kinect then becomes very unresponsive and the video showing depth of field is very messy and has artifacts.

The Kinect Tuner without the Zoom attachment has a clean image.

Dance Central without the Zoom attachment has a clean image, but can hardly fit me in.

The Kinect Tuner with the Zoom attachment has a dirty image with lots of black.

The Kinect Tuner Tracking screen fails to detect the floor with the Zoom attachment on. Retrying usually fails. Without the Zoom, this step works fine.

Dance Central with the Zoom attachment on fits me in better, but has lots of blurred shapes on the bottom of the screen, usually at my feet or the carpet. The game becomes very unresponsive.
With the Zoom attachment on, it also becomes really hard to navigate menus or move cursors around the screen.
I stand around 4 - 5 feet away from the TV and then there is a couch and a wall behind me.
Have also:
- tried having the Kinect sitting just below the TV but that didn't help.
- experimented with the Tracking and Calibration screens a fair bit to no avail.
- wiped both the Kinect and Zoom lens with a soft cloth to remove dust.
How do I get the Zoom and Kinect working together reliably? Could the Zoom be defective?