Hello, I have a MacPro 3.1 and I have a weird problem. When I'm using MacOS my second monitor, a Samsung TV, is working great. When I'm on Windows XP (unfortunately I'm using some programs for machines that are working only in XP) my secondary monitor is not working. But if I connect a second 17-inch display, it is working just fine. I have updated my system and still the same. Is there anything I can do? I need it for presentations. Thanks in advance. ps: I wish I didn't have to use windows!!!!