Originally Posted by the.Mtn.Man
So apparently it can withstand coffee on the screen but not a light tap from a mini-USB cable.
This is probably because the problem is caused by the diffraction grating for the lights, which I would guess takes the form of etching in the screen, which has weakened it slightly versus impacts.
When the grating is damaged, light isn't distributed properly any more, and you get a "pool" of light at the point of impact. That is my take, anyway.