Change state of "Next" button works in preview mode but not after publishing.

I created a menu - containing 5 sections - where the "Next" button is disabled and after visiting all mandatory sections (3 out of 5) change back to state "Normal". I have a variable defined to keep track of the mandatory sections visited.

The variable changes value and the state change works fine in preview mode but once publishe and viewed in IE the variable doesn't change value and the "Next" state remains disabled.

Anyone how can help me out with this?

Patrick