Susan,
Do those 3 click boxes display a different text caption? And do they have to remain visible all 3? And what if a user clicks twice the same click box, the counter will be incremented. Either you disable the click box once it is clicked (can be done in the same standard action), or you use 3 variables, one for each click box that are toggled and you check if they are clicked the three of them.
Showing the Next button can be done by the actions on the click boxes, have several examples on my blog. The idea is that you have a conditional action with two decisions, the first is a mimicked standard action. It will be something like this (I keep the same logic, but disable the click box to avoid having it clicked a second time):
1st decision Always
IF 1 is equal to 1
Show Marketplace_text_1
Expression v_counter = v_counter + 1
Disable ClickBox1
2nd decision CheckAll
IF v_counter is equal to 3
Show Bt_Next
Since Captivate is always evaluating everything, this will result in what you tried, without having to replay the slide. Or do I understand your question wrong?
Lilybiri