Can't undock CRJ displays

I’ve read all the posts here and elsewhere on undocking the displays, but for some reason it’s not working for me on the Aerosoft CRJ. I get the little finger pointer over the displays, but when I press ALT, or AlT CTRL nothing happens.
Am I missing something?

Hold the right ALT key, and click on the display with the mouse.

Yeah, I do that … nothing happens.