Question 3x3 Flipbooks don't work?

Hello there. I am getting strange behavior from the flipbook node. When using any other size of flip book, it works fine, but when the width is a multiple of 3, it has problems.
Every third(or 6th, or 9th, etc.) tile, it loops back and displays the wrong one( he one two tiles prior). For example, here is an image:

And here are the nodes:

At tile 0, it will show 0,
At 1, it will show one,
At 2, it will show two,
but at 3 it will show 0 again
and it will glitch out every third one continuing on.
It works with every other size of flipbook, so I'm not sure what's going on here.
Thanks for your help!