panasonic pv-gs19 minidv pc connection help needed

i have had this unit(panasonic pv-gs19) for a 2 years it worked fine on xp i upgraded to windows 7 and now it doesnt work, im using firewire, its not working with vista either,i have tried 32 and 64 bit, works on my mates laptop runnin xp, i have checked all my hardware and other devices work so i dont think its my firewire card or cable..anyone have a solution any help greatly appreciated