I just discovered a rather strange problem when I connected my MacBook up to my 23" ACD monitor. I'm also use a keyboard connected via USB to the display and then connecting through the DVI to ADC adapter. The symptom is around switching between full screen and windowed display of the Windows XP desktop. When using this over the last couple of days on the MacBook everything was working just fine including the resolution swaps and all. Today I connected up to the larger display and I'm having all sorts of problems with the switching. I can get it to switch into full screen mode but I cannot get it to switch out no matter what I do. I tried it in mirrored mode as well as extended desktop mode and the symptoms are identical. The only way I can get back to using OSX is to either force quit Paralles (not desirable) or choose Command-Q and then cancel the shutdown of Parallels. Edit: Never mind, I just found the answer in another thread. Pilot-error on my part.