As noted, it's my DX10 code; I need to get a new video card. And other expenses...
Yea, looks like uninitialized memory to me (that 1.#Q is a good hint and probably NaN). I'd look at the Direct3D 11 Tutorials that come with the SDK (specifically tutorial #4) and create a constant buffer, fill it with the data you want, and then set it for your pixel shader so it can access the data. Very simple process and will give you more control/better results of your data anyway.
I've used SlimDX before and its going to be VERY similar to the D3D tutorial (just more object based since SlimDX is a simple wrapper on top of the normal SDK).
Edit: Just to clarify, I meant to ask if DX10 versus DX11 changes the tutorial I should look at, but the question probably wasn't clear. Don't want to implement DX11 code that has a silent error if ported to DX10 or something, after all.