Wow i have to say this is a new one for me.Never seen anything like it but would love to know what caused it in case i ever run into the problem.However i will say that changing a FAT32 disk to NTFS is not needed.I have a main 40GB,slave 80,and second slave 120GB when i upgraded from windows ME to XP pro i formated my main drive to NTFS and left the two slaves as FAT32 and never had a problem.I later converted them and still had no troubles.