You could try uninstalling ffdshow (with using it or not having the same results), but this doesn't seem to be a codec problem.
There will be a D2:ED patch released after FoV and DKS are out (included with FoV), and a large D2:ED+FoV to DKS conversion patch (which would have to come through D2D for that release). With a limited return time, though, it would probably be safer to return it and wait for DKS.
Unfortunately, I don't know of anything else to suggest that you haven't tried or isn't in any of the topics already referred to.
