Yeah, I recently got a "Save file is corrupt, data couldn't be written on selected device. Autosave will be disabled" or something like that message in Rock Band 2. Luckily I followed the steps here so I didn't loose any progress, but I wonder... why does this happen? It would make sense if only people using RawkSD or some other mod got this message, but it seems anyone can get it. By the way, the problem seems to be related to DLC... I got this message after playing a Green Day DLC song, if it matters.