Hi Ramiro, have you tried rsync with ffs in that drive? If it's ext2 implementation's fault, you could try udf, If I remember correctly udf file system checking was added recently to netbsd. I have used ntfs-3g in the past but with bad performance I suppose due to netbsd's fuse implementation, on freebsd ntfs-3g has very good performance and I use it in pendrives when I don't know what os is going to read them.
Good luck, adr
