I am a longtime mac user, and I have a problem that is baffling me! I work at a college, and we have daily chapel services, and guest speakers will often bring their laptop to run their powerpoint or videos or whatever through our system. We hook them up through our VGA switcher/splitter. I have noticed that if I hook up a macbook (a regular macbook, such as my blackbook) everything works fine...BUT if I hook up a Macbook pro, it never works. I figured it was a problem with our switcher/splitter, but I have tried it with two different splitters and the same things happens! Has anybody else had this problem?