Distorted Display - mini display port to Dell ST2420L dvi connection

I am having problem with connecting my new Macbook Air to external display.

I have tried restarting both the Macbook and Dell monitors and installing latest Lion OS updates.

The connection is from mini display to dvi adapter from Apple and a dvi to dvi cable connecting to the rear of the monitor

The monitor works fine with both VGA and HDMI inputs and DVI input from PC

Here is a picture of the distorted display http://t.co/yVdmCfl

Please help

Thanks

Aditya