CUDA/D3D interop error under Windows 10

I’m experiencing a sudden CUDA error in an application I’m developing which uses CUDA-D3D9 interop. The error occurs specifically on a laptop with a 750M & Windows 10 and display driver 353.90, but does NOT occur on the same machine with Windows 7 OR with Windows 10 and an old display driver (347.62-- the driver included in the CUDA 7.0.28 installer).

Specifically, when registering a texture for interop, cudaGraphicsD3D9RegisterResource returns “operation not supported.” Are there any known issues under Windows 10 which would cause D3D interop calls to fail like this on some machines (laptop, 750M), but not others (desktops with Titan X & GTX 580)? Until now, the interop registration calls have succeeded on all machines with all SDK versions since CUDA 4.0 and all display drivers.

To answer my own question: it was caused by the dropping of support for IDirect3D9. Switching to IDirect3D9Ex fixed it.