I have also samekinda problme with my CoD2.
I just updated my rig including gpu from GTX560 to R9 280x. After that , I have had somekinda weird lagg (mostly vertical) in CoD2. It looks like my fps is 15 when I move my mouse. Changing fps doesn't help at all.
Also, it feels like my mouse's dpi is way over 4000, so aiming is really hard.
And this all happens only in CoD2.