Graphics drivers would be the obvious suggestion. First go to your graphics card maanufacturers site and get the latest, then go to
www.glsetup.com and run that. Fixes most driver probs in my experience.
Other than that, in the config program theres an option for soft cursor blits. Find it and enable it. Itll stop the graphics card bollocksing up the mouse cursors. I dunno how *anything* could screw up the mouse cursor like this though, its a fairly common thing after all.