I have recently purchased an MS IntelliMouse Optical for my G3 b/w 450, installed the latest software (IntelliPoint 1.1) but it doesn't work. The light is going on when plugged into the USB port but the cursor is inactive. I have tried different surfaces just in case but no response. Do I need to uninstall the Apple Mouse software or something? My understanding is that I should in fact be able to use more than one mouse if I so desired with USB. Anyone else have this problem or a solution...???