I just finished hard and I'm not ashamed to say I suck at easy.
going backwards is hard because you are used to playing all these extra notes and now you only have to play a small fraction of them.
I really doubt its the guitar, it would either work all of the time or not, it doesn't know that you are on easy difficulty so it couldn't just be playing up on that difficulty.
face it, you have 2 options, your disk is damaged somehow (scratched/dirty/not recorded to properly) over the part that reads the easy section of the game somewhere, or you are missing notes like everybody else does. and I do mean EVERYBODY else does, you can not 100% every song every single time you play it, even proffessional musicians stuff up sometimes in songs they have played every night for years, it just happens
Az
30/12/2007
Mario Kart Wii
Tasmania