We're discussing this now, and the team is informed. I'm sorry, but this may take some time now.
This only affects user of a real Wood R4i Gold 3DS (r4ids.cn) that used this flash files for the real Wood R4iDSN (r4idsn.com). I know 4-5 guys that actually did that. And if some hardcore Wood nerds tried that, some kids will do that, too.
We need to know now why this happens. It doesn't seem normal that a flash cart erases your Micro SDHC card completely. That's a very serious issue.