If you get the glitch,erase all yaiba data, put your profile on usb,load up game and pull out usb as the spark logo appears,you will see message saying insert device,dont,start new game all stats should be reset like you havent played before,once you start new game insert device right after selecting,then play thru on easy earning upgrades again,
i tried this after 3 unsuccessful playthrus after erasing data,hope it helps!!!