AWOL:
What? There are 10 elements (LED's) I don't quite understand
Ten elements 0 to 9 correct, so what happens when you try to address element, say,400?
There aren't any numbers in this code over 10 so I don't see any kind of problem there. Also, when 10 is mentioned it is like this "... < 10" which means anything LESS than 10, so nothing can be above?