Enabling Direct3D-specific features (transparency AA)

Question

Hello. I am trying to enable transparency antialiasing in my Ogre-Direct3D application, but it just won't work.

HRESULT hres = d3dSystem->getDevice()->SetRenderState(D3DRS_ADAPTIVETESS_Y, (D3DFORMAT)MAKEFOURCC('S', 'S', 'A', 'A'));
/// returned value : hres == S_OK !

This method is taken from NVidia's technical report.

I can enable transparency AA manually through the NVIDIA Control Panel, but surely I can't ask my users to do it like this. Anyone has any idea?

Thank you for your time,

Bill