Storyline seekbar question

Hi,

I'd like to include the seekbar, next and previous buttons on a few slides within one scene. I do this by clicking on the slide properties wheel and selecting 'custom for selected slides.' This works fine in preview mode, but when I preview the entire project, although the seekbar and prev/next buttons do not show on the slides where I do not want them to show is correct, the actual white area is showing. So the resulting slide objects are pushed up higher on the slide with a big chunk of white space showing on the bottom of the slide.

Is there a way to NOT have this extra white space show on the slides where I do not want these player features?

Thank you for your input.