There is improved DX compatability testing in next release so that Windows machines that don't have hardware accelerated DX7 present will return a Null D3D7GraphicsDevice.
Flameduck, there still may be some issues with machines using systemmemory for textures that could have affected your testing sofar also.
Flameduck, there still may be some issues with machines using systemmemory for textures that could have affected your testing sofar also.