3D Screen saver won’t work

I have a Radeon 9250 128mb/128bit AGP installed and works fine… except it won’t show the 3D screen savers. I have installed them properly, but although I can preview them without a problem, when I select one from the list of screen savers and click Apply, then OK, it never starts up. I go back into Display Properties and it is not selected anymore. Why is this and how can I fix it? Apart from getting a better AGP card.. for now