i just bought a mdp to hdmi adapter for my 13"mbp, to connect to my exteranl monitor (dell 2408wfp) however when i try to connect i get no picture on the display i see glimpses of the screen but then the display switches to powersave if i boot the mb and then close the lid i also see the start up screen but then it goes, i have tried it on my hdtv and it works fine does this mean the problem is with the monitor? i had it working fine through the dvi cable on my old mb