Slide layers

How do I avoid the following problem when using slide layers.

Slide has a question with feedback appearing on a slide layer. The slide layer is shown and the learner moves to the next slide, they then decide to click the previous button I then find that I have the main slide displayed along with the layer information which makes it impossible to read. What I want them to do is go back to the previous main slide.

Also is there a way of resetting a freeform drag and drop, I am thinking the learner completes the exercises then moves to the next slide, they click the previous button and it would be good if the drag and drop is returned to its original status, what is the trigger for this?