Okay it is due to one of your files (Most commonly common.3) being over the size limit
oh okay, well I'm about to try it without common3 so hope it works, the thing is, I don't realy get how it could be my common3 (or any other file) because, I didn't add anything to my sdcard... only 2 codes...
or a bad replacement on the iso if u use wiiscrubber. i also had this happen when a movie file replaced wrong on the iso.
and well, I'm not editing my ISO, so... EDIT: removing the common3 from my sdcard didn't work...
its the alternate stage loader code, maybe it just doesn't work with usbloaders?
same goes for projectM btw, doesn't work for me:P