My Zagg Shield is doing great on both my Incredible and Ipod touch, the touch has had it for almost two years and still looks new, maybe you guys have no clue how to install it, there is no reason for dust and dirt to be under the shield or under the edges, follow the instructions real slow, make sure you are in a DUST FREE environment, make sure your greasy fingers are cleaned with soap and dried with a nice clean fresh towel "you should have on of those around the house I hope".
First clean your screen with the cloth that was supplied with the shield, make sure there is no lint or dust spots on the screen "yes you can see them", if there is clean it again, spray your fingers and the screen with the solution, now peel off one corner"the top side of the phone section of the shield" of the shield from the backing, make sure you peel it towards the other side, peel it downwards about half an inch, now line it up at the top, once lined up get a credit card or the zagg card and start sliding it accross the shield "make sure the shield is also wet on the top side", as you slide the card downwards and setting the shield, you will be also releasing the remaining shield from its backing without getting your greassy fingers all over it "you need a steady hand, and lots of patience", once shield is installed, keep wetting the top while you use the credit card or zagg card and start pusshing out the liquid that is under the screen, yes it will take some time, as I said before patience is the key.