Hi Zain,
I think the problem is that your the operating system on your PF has formatted the card in a different FAT system than the camera can recognise. Windows decides based on the size of the card which FAT system to use. If re-formatting the card in your own camera does not work (as suggested by your e-mail) try re-formatting the card in any other device (not PC) you can find. It has helpd me out a few times when I ran into the same problem.
hope this helps
Paulus de Boskabouter
June 2007