[PPCFreak]

nothing to do with Android. mine has it and had it before messing with Android.

Has to do with the layers of screen (not sure of the techincal term) becoming spearated.

Can happen due to excessive pressure on the screen (mine happend when my 3yr old son decided to punch me in the pocket....and so happened my phone was in that pocket with screen facing out).

Only way to fix that I am aware of is replacing the device.