Locking down custom interactions

hi there, 

I have a course that is locked down.  The problem is that I have 2 custom interactions.

They both have 3 buttons which hyperlink to hidden slides within the course.  When the Forward button is clicked on each hidden slide you are then brought back to the initial screen, where you have to then click the other buttons in order to proceed.  The problem is that when I click the 3rd button first and then go back to the initial screen, I'm allowed to continue on without having the click the other 2 buttons. This only happens when I click in this sequence. If I click them numerically the Forward button remains locked on the initial screen until all 3 buttons/screens are accessed.

Any ideas how I can force the lock down of the main screen for custom interactions?