So no one has an answer? I have a support request into AMD as well but that seems to be a black hole. I was at least able to get it to work but only when switching from a cloned setup to a vertically stretched setup, which is what I want. The only real problem with that is that it did not work when there was a fresh install of Windows XP (the embedded target) with the monitors in that cloned configuration. But if I set it to cloned through the Catalyst Control center then my code could successfully switch it to vertically stretched.