I found something about it. I do use the "Native Ingame Trainer". If I go in and play the game regularly, none of this happens. But if I ever have to use the "Teleport" function of the trainer, where the game to recreate a different scenery in a flash, apparently that put a massive strain on the GPU, causing the processing speed to slow down, thus slowing the visual speed. Or maybe I'm just imagining things, could be just the refresh rate problem...? Anyone else got any ideas?