BootMii suddenly doesn't like my SD card

I've been using an 8GB Kodak SDHC card for quite a while. Suddenly, as of today, BootMii boot2 freezes on startup when using this card (my other cards still work). The drive light flashes twice, but the Wii doesn't boot at all.

The only change I made was moving some Wii data off the NAND to the SDHC (it was DLC for FF4TAY) and downloading the updated version of Cave Story from the Shop.

Testing shows that deleting the entire 'private' directory of official Wii data revolves this issue.

Any idea if this is an issue with some kind of DRM that might be on those files I moved? Or possibly something to do with BootMii being able to handle cards that are 'only so full'? It's a very weird error.

There could have been an error on the SD card that was fixed when you plugged it into the computer. Maybe your computer noticed this, and fixed it without telling you. Just an idea though.

I've narrowed the culprit down to 3 possibilities:

loc.bak (located in private\wii)
loc.dat (located in private\wii)
77463445 (the folder that contained the FF4TAY DLC, located in private\wii\title)

Have you run a disk checker on it, like scandisk or chkdsk? Bootmii doesn't care about those files, so it sounds like the filesystem is messed up somehow.

Yeah, I ran the scandisk utility and it said if fixed some errors, but the card still wouldn't work with BootMii. Only removing those three files fixed it.