ok i just figgured this out for myself, im assuming u have the universal customizer on your computer right? well if you do go to the directory of it, then go to the U3CUSTOM folder. place anyfiles you want in here, just your autorun will be fine as it will point to the non cd partion. ok now go back one directory to the universal customizer folder and click on the ISOcreate.cmd file. this will create your iso in the bin folder for you. ok leave it there for now because its in the right spot. now run the universal customiser and install wat ever to ur U3 drive. done! you might want to back it up first or if you have the latest u3 update for ur usb you can just use that to make everything back to normal.