Your graphics card acting up and whatever framerate or frame skipping you get has nothing to do with what we see when specing you, so that's that. Now, even if your skipping was somehow caused by other technical problems (rates, connection, etc.), you still sometimes move too fast. What about that?
I for one can confirm that I've seen you both skipping around and running too fast. It was a while back in militia and you were playing by the name [ m y g 0 t f 0 r g 0 t ] and I was specing when you ran the whole long side of the sewers in a flash. People tried votebanning you then, which never works.