SlideShowPro Player for Lightroom uses Javascript to scale, align and size your slideshow in the browser window. This allows the SWF to always remain centered (horizontally / vertically), but also apply scroll bars should the end-user's browser window be too small for your published slideshow size.
To facilitate this, "loader.swf" must be able to communicate with Javascript in your browser. This works as expected when viewed online, but may cause problems when viewed locally for the Flash Player may block the interaction (for security reasons).
So if you preview your exported content locally and see a blank browser window, or the scroll bar functionality isn't working correctly, you may either upload your content to your web server and preview from there, or follow these instructions to change your Flash Player security settings. Here's how.
Visit the URL below:
http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager04.html
This screen displays the security settings for the Flash Player plugin. In the Settings Manager box (shown right) click the "Edit locations..." drop-down. When open select "Add location...". A dialog window will appear containing a "Browse for folder..." button. Click the button. An operating system window will appear asking you to choose a folder. We recommend choosing your "Desktop", since that's the most likely place you'd be exporting your slideshow to.
When selected, the path to your Desktop should appear in the "Always trust files in these locations:" box at the bottom of Settings Manager (shown right).
Refresh the browser window containing Settings Manager. This will save your new preferences.
With Step Two complete, and with your exported slideshow folder on your Desktop (or alternate location if setup differently above) double click on the exported "index.html" document. The slideshow should appear and behave normally.