simple set up with Mac OS X 10.7.5

[arussel]

I have a OSX 10.7.5, I'm using a screen attached via the 'normal' external video and was hoping to be able to add a third screen (laptop + first external) following this:
http://gigaom.com/2010/10/07/quick-t...s-to-your-mac/

I bought a samsung screen and the usbtovgae2 and install the displaylinnk driver (I've tried with 1.8 and 2.0 alpha). I was expecting after rebooting and plugin the usb to have a blue screen on the usb display, but ends up with neither a blue screen or being able to see the screen in preferences-> display.

I'm probably doing something really stupid but can't find out what, any help welcome.

Alex