This just in... ...Final Fantasy Dissidia (import) and DJ Max Fever are checking your memory card for remnents of custom firmware. Basically it checks for ms0://seplugins and ms0://iso. When it finds it, it takes "unexpected action", which according to some sources state,
Now not all people are getting the same stuff going on, it seems to be hit or miss kind of thing, and this seems to only happen on booting UMD's. But if you are having trouble with these games from the UMD, you need to download "CFW Folder Blocker 1.1", and have it block umd's from accessing either /iso or /seplugins.Dissida : Final Fantasy deletes a few plugins, particularly cwcheat
DJ Max : wonÂ’t boot if Â“.isoÂ” files are found on the memory stick.