I have a couple of threads about this issue. HTC is aware of this issue regarding the touch screen. Sprint is aware of the issue also, at least some of the stores are aware of it. It is a separation issue of the internal layers that the touch screen is composed of. It starts out as a small rectangle which progressively gets larger until the touch screen becomes unusable regarding not being responsive to any touch. You then have to use the "hard" buttons. The process from small rectangle to complete failure took approximately 2 months for me at which time I received a replacement. This issue is not the fault of the user and is a manufacturing issue. Other non HTC touch screen devices have similar issues including blackberries according to the Sprint store reps I spoke to. Sprint treats this as a manufacturing warranty issue and don't let them tell you otherwise. I had no problems replacing my Diamond when the time came. Sprint was very good about it
EDIT:You can read more here>>
http://forum.ppcgeeks.com/showthread...mond+has+worms