I'm experimenting with setting various graphical settings in my Direct3D9 application, and I'm currently facing a curious problem with anti-aliasing. When running under the debug runtime, AA works as expected, and I don't have any errors or warnings. But when running under the retail runtime, the image isn't anti-aliased at all. I don't get any errors, the device creates and executes just fine.

As I honestly have little idea where the problem is, I will simply give a relatively high-level overview of the architecture involved, rather than specific problematic code. Simply put, I render my 3D content to a texture, which I then render to the back buffer.

Any suggestions as to where to look?