Record screen got a gray recording... nothing else

We've been given the assignment of creating e-learning for one of our products which runs on a POS (point-of-sale) terminal; we're switching to Storyline for everything else, so we'd like to use it for this as well.   The terminals run a variation of Win XP (POSReady 2009) and we were able to install the 30-day demo version of Storyline on one of them to prove it could be done and the machine didn't crash or catch fire.

We tired a really quick screen capture session to see what would happen when we captured the application, but the screen didn't capture- we got a gray screen.  The app in question is a JAVA app running in Java Runtime environment.  Is there something special I need to do to capture a JAVA app, or is this a function of taxing this "smart cash register" to it's limits?