im having problems with my GD87, the screen keeps going blank somtimes after i recive a text or end a call. it goes completly blank i then have to turn it off then back on again. i dont think its the batery as when iturn it on again the battery has a full charge is anybody else having the same problems with the same or differnt phone? and does anybody have an idea of why it is doing this? and how it can be fixed?