Hi JonnyC289,
what you're seeing is an artefact that I think everybody will be seeing, so I wouldn't call it an NVidia error. It's more just a side affect of using a game engine designed for First Person Shooters as a basis for a top-down RTS.
Unfortunately it's a bit of a rounding issue in the hardware that's causing the issue, and it's particularly worsened by low and gradually moving light, both of which occur quite frequently in the game.
That said, we don't think it's a huge matter for concern and look forward to innovations in the engine that help us alleviate it.