This is a common misunderstanding.
Make sure the pause point of the click box is at some point AFTER the pause points of the buttons. If all the objects on the slide are set to pause at the same moment then clicking any one of them will cause the slide to continue.
It would be better to post a screenshot of the timeline as well. And do you want to give the users the opportunity to choose multiple times? How do you want them to proceed to the next slide? The default pausing point of a button is at 1.5secs, for a click box at the end of its timeline. If you kept the default duration for the slide, this means that the click box has its pause after the pausing of the buttons. But this cannot be detected from your screenshot of the timeline.
Default design is that when a Success simple action is executed for an interactive object, the play head will be released at the same time. You didn't explain how the variable is populated by the buttons, is it by a simple action 'Assign varLength with...'? When the user has clicked one button, play head will move and stop at the pause point of the click box. If all the buttons are pausing at 1.5secs, this means that the other buttons cannot be clicked anymore because the playhead is in the inactive part.
Maybe Rod's answer will solve your problem, if you indeed did change the pausing timing. Another way is to replace the simple action by a standard action, because then the playhead will not be released. And user will be able to change his mind and click another button.
Thank you Lilybiri - it seems as though what I needed was to Execute Advanced Actions rather than using the simple actions. Your video was very helpful.
In response to how they will procede - I will just add a simple next button onto the slide.
I have modified the action buttons so the assign the valsue to the variable via the Execute Advanced Actions and yes, the playhead does not move so everything at it seems to be working - thanks again.
Rodward - thanks for your post, however I am sure in older versions of Captivate you could specify where the pause point was in a click box (I could be wrong), but I noticed this is not available in CP6, unless I was not looing in the right place.
Seem vaguely to remember something like that about click boxes, but was before version 5. And it really has no sense because a click box is invisible to the user, why have a choice for pausing point?
Could you mark the thread as answered?