I have a logitech MX 300 running at 1000hz confirmed via mouserate and several other programs like that. I am using the Markc Win7 64bit mousefix and confirmed that it is active. I don't have any logitech drivers installed either.

Now when in Blackops and I do a slow 360° and then swing the mouse back fast to its original movement point I experience quite some negative acceleration. The faster I move the mouse the more I get.

With the Logitech G3 which has way lower perfect control speed I get no negative acceleration at all.

Any ideas?