Huh? It seems odd. The 30" ACD is a display panel like any other with a DVI to display images either by a computer or another source.
Did you check the system specs on the apple website to see if they match? I think it should all be plug and play now-a-days.
You could try
http://support.apple.com/kb/HT2810
http://support.apple.com/manuals/#displays and compare against the specs on http://www.bang-olufsen.com/specifications?productid=135
And check that you've got it on the right output/ input ;-)
Mick.