Smart Media Card Readers

Hi.
Just a cautionary tale, which may help anyone who finds themselves in my situation

My digital camera Smart media cards were both full of holiday snaps, so after downloading all the pictures to My Pictures, I decided to format the cards ready for more masterpieces.
So using the format option on the removable drive, I cleared the cards. Then away to take more photos. But when I tried to see the new pictures on the PC no images were shown, although the cards were saying that an amount of memory had been used, and my camera, an Olympus, was saying that photographs had indeed been written onto the card.
I tried with both smartmedia cards, and got the same result.
So then I formatted the cards using Olympus`s own software, with the result that not only were now no images being shown, but I now was being told that the cards were either empty or write-protected!
In desperation I then tried using the smart card reader, (Zio), software, and surprise, surprise , it worked!

After thinking about it for a bit, I realised that since the last successful format, using Windows removable drive formatting, I had changed from Windows ME to XP Pro, which obviously does not suport this function now.
Could this be due to a differing FAT function?