Stop Watch

This Stopwatch dont work correct: in 00:30:00 min its only shows "00:29:56:xx" ( xx is a number but this don't change anything ). I think, there should be a other (better?) way to do this. (I think a calculation with "MILLISEC" and using "VSYNC" can be better work, but I don't have tested until now.) Edit: The Problem ist the Frame-rate of the 3DS that isnt exact 60 Frames. Using MILLISEC don't helped ; only a framerate by 59,834 frames per second sems to work fine. So it sems, that i cant fix this error without rewrite the code in a differnt way.