I'm not sure, Nebula, but I will give a run with it off a go. I don't recall having this problem in an install I had a little over a year ago, though whether I had NanoFX eludes me. Still, MLeo's right as far as I know; a simple resize shouldn't be doing this. Hell, the speculars in the pack have only a fourth of the pixels of the maps they regulate illumination for, so I don't even think their size is a relevant factor.
Edit: That's not it, either. So it's likely something I'm doing. . .or not doing. I just can't fathom what it is at the moment.