Substraction of frames_count over 24h while calculation SMPTE is corrupted

So I came along this frame_count *1412630992027* while framerate is *25*. 
This should result in a SMPTE similiar to *23:29:52:00*.
But I got this: *23:NaN:NaN:NaN*

After looking into the function, I discovered an interessting bug (or two).
I fixed them and both.