Ok, here is something that seems to improve the situation for anyone else having these issues, it's not perfect, but a noticible improvement. First, play with the Direct X version. If you bought the game from GOG (or elsewhere) as I did, try the demo version of this from the Spiderware version. Then set your Compatability mode to Windows XP (I also run as administrator and "check" disable display scaling for what it is worth). There are still some jerky movements, but combat always runs more smoothly. If this fix works you can always explain your situation (and verify your purchase) to Jeff and request a key, he seems willing to send you one to enable this mode. Hope this helps. If anyone finds a better solution let me know please.