I guess you have discovered this (see title). My son has a PSP and I applied his SP for him--wasn't rocket science and now you would be hard-pressed to tell it was on there. Of course, the PSP has a hard, polycarbonate covered screen. I was able to press and "squeegee" quite hard to get a bubbleless surface. I can't see that happening with a 770--as your experience validates. I would say that by the time you actually start to gt a ragged display from all the use it will be time to upgrade anyway. Don't get mad, get even--invent something better. BTW, good luck.