Is the top or bottom of each slide cut off when you preview or publish your Storyline project? We've found that this can occur if you customized the player while using the original software release of Storyline, and then you later installed Update 1 for your Storyline software.
This issue was corrected in Update 2 for Storyline. To take advantage of the new features and fixes, download and install the latest version of Storyline from the link in your product confirmation email, or get it here. Then republish your Storyline project.