Adding more programs to the Programs tab?

For some reason when I get to the bottom of the list when adding programs to the programs tab a new empty box appears but I cant add anything to it. If I try it just goes back to being blank and a new one appears next to it. This is really annoying. Are we suppose to be able to add as many as we want and mine is broken that way or are we not suppose to make anymore and mine is broke for adding new boxes?

On my fience diamond when I add stuff to the last cell thats all, no new boxes.