that could the problem remember that:
FAT16 has a 2gig size limit (under win9.x and me)
FAT32 has a 4gig size limit
FAT16 under NT or 2000 has a 4gig size limit
and the NTFS file system has a (theoretical) maximum file size of
16 exabytes or 18,446,744,073,709,551,616 bytes
that's why i only use ntfs
if you're running a fat file system then try using scandisc to fix errors.