Do you have the "FrameRate" manager active? It could be the distance sliders increasing/decreasing draw distances on the fly in response to FPS changes. Try disabling the FrameRate manager and then go into your (game) video options and maxing things out. See if that helps.
I'll defer to ol' Supierce on this one. I'm not sure off the top of my head. You can check by going in-game and changing texture size, exiting, then checking those settings that Supierce mentioned. If they change, you have your settings.