I just upgraded to a 6650 with the S60 operating system, but previously had the 6555 with the S40 system. I prefer the S40 system because the menu navigation is easier for me. Is there a way to convert my 6650 phone from the S60 OS to having the S40 instead? I love the hardware features of the 6650 (bigger screen, memory card slot on side, changing keypad color lights, etc), but find the menu a bit challenging to navigate. Help please Thanks!