Hi Blindside,
I'm currently updating my Nvidia drivers, I'll let you know how that turns out. I'm guessing you're probably right about the phong effects, should I try to address that somehow?
Also, the error is literally: "Error setting float array for HLSL variable"
That line is copy+pasted from my output window. It prints it out every frame, too.
I'm about to restart my computer and test the updated drivers, I'll be back shortly

I'll give a test to OpenGL too, but I was having issues with OpenGL (unrelated to XEffects, don't worry!) before so those issues may still be lingering.
UPDATE: Okay, after updating the drivers, I ran it again, and now most of my scene isn't there

The moving billboard and the skybox are there, but all of my meshes are invisible.
However!!
On a brighter note, I ran it with Open_GL and it ran swimmingly! It didn't get the float setting error either... I'm really conflicted over it now, because I think I'd rather use Direct3D9 but I can't seem to get it working correctly

However, I'm glad to say it definitely looks like it's not a lost cause, and it's related to my Direct3D setup.
Any ideas on how to jump that particular hurdle?

Thanks again, I'm so excited to see any of this running! A few hours ago I thought it would never happen
