Hacking Is my NAND backup bad?

[megatron_lives]

Hi all.

I'm trying to transfer saves from a NAND backup I made from a now bricked 4.2E Wii to a new wii. I understand what to do, but I suspect my NAND backup is bad.

When I open nandextractor there is only one file under each heading (shared1, title etc.) listed as ??????????. And when I try to extract all, it says it can't "open files for writing"

I backed up the nand on a Play.com sd card and it verified and everything seemed fine.

So is there anyway to test if the NAND is a bad dump, or has what I've done above more or less done that?

Also, if the NAND is bad, what can I do in the future to avoid generating a bad dump - use a more compatable SD/microsd card I suppose?

Thanks

Mark