Problems with mouse in FS9

Hi GuysFor some reason in FS9 my mouse scrolls very slowly. If I press the "alt" button to access the menus it works properly, it only slows down in the cockpit and also on the "create a flight" menus. This is a new problem as it worked fine up until now. I have not installed any new software or hardware recently. Any ideas?Microsoft XP ProfessionalPentium 4 2.2GHZ512mb RAMnVidia GeForce 4 128mbMicrosoft Forcefeedback JoystickLogictech Trackball mouseThank you Gerry