Dunno... my "normal" Mac USB mouse is listed at devices. I wonder that the mouse vanishes because in Sins of a Solar empire it vanishes when I switch off the Smart Mouse but not when I enable the USB Mouse in windows and leave Smart Mouse on. Actually it should not changed the mouse cursor at all IMHO... as the additional mouse is just an additional way to move the existing cursor.. 
Anyway... I believe that the Parallels guys should look into this problems again. Its a pitty to have everything right in the game but moving the mouse :/
Anyway... I believe that the Parallels guys should look into this problems again. Its a pitty to have everything right in the game but moving the mouse :/