To add a little more info: I have an optical, USB mouse. I just d-loaded its latest driver from Microsoft; no good. I unloaded and re-loaded the game; no good. THe mouse is sticky on the main screen, and is confined to the bottom on the scenario selection screen. Often it becomes "sticky;" leaping about, not moving smoothly, oftn not moving at all, often freezing out entirely. The arrow keyboard keys don't effect this screen ever, as far as Iknow. I've tried the number pad, as well as the four regular arrow keys.(I'm not running the "Logitec" option on the mouse control panel. Thanks