I can't say I understand why this is happening.
My Wife has an Eris. I bought her an accessory pack. It cam with some generic chargers, car and wall. When her Eris is plugged into the wall charger the screen won't unlock and if you press the menu button to unlock it it just keeps vibrating.
I thought this was odd since it charges the phone perfectly.
So then my accessory pack arrives for my Incredible. Same thing. When I plug my Incredible into this generic wall charger, it charges just fine, but it's won't unlock using the touch screen and if you press the menu button it just sits there and vibrates.
I'm going to buy some adapters at Verizon instead but I find it odd that these chargers will not only charge as they are supposed to do but they lock two different model phones up...just because they are generic?
Anyone else experience this?