Then this post might help you out!
Recently I bought a new mouse, the Logitech G9x beside the fact that I felt really uncomfortable with the size of the mouse, it also responded with a slight but noticeable delay in some older Games, including Elite Force II. In fact the mouse was terribly slow while being inside the game options.
The precision of the mouse in newer games was great thou, so I went back to the store returned the mouse and I bought the G500 which had a familiar design. But I got the same issues there too, so I tried to update the Setpoint Software. Setpoint told me that it was up to date, even thou I installed it from CD and the latest version online was quite different compared to the version on the CD. Setpoint also didn't recognize my Logitech Keyboard...
How ever, after several tries to fix and update the Software, I decided to uninstall it, since I don't use the features of the Software anyway. After rebooting my PC the mouse started to work perfectly with the older games again. After a few tests I realized that I had the same kind of delay with my old MX518, when the Setpoint Software was installed, but it was barley noticeable with that mouse.
How ever, if you have the same issues, just try to update the Software or uninstall it and it should be fine again.