I have the 8120 and there is a symbol in the top right hand corner that I have seen before but I cannot figure out how to remove it from the screen. The symbol is a black rectangle that has been scewed a bit with the "NUM" letters inside of it. When I press the "ALT", the symbol changes to the "DNP". What do these symbols mean and how do I get this symbol off the screen? I am having a some difficulty with some functions on my phone while this is on.