For some reason, I have a lot less resolution options in Quickres when I upgraded from XP to Win7. Instead of switching the resolution through Quickres, I right click the desktop. Click on Screen Resolution then Advanced Settings then List All Modes. There should be a ton of resolutions to pick from. This is especially nice if you're switching between an arcade monitor and a PC monitor frequently because all the Hertz options are there too.
Not sure about the Video Plugin problem though. I haven't tried demul