Interesting, but the problem has come back on both iPads, and the solution is not only to kill the app and restart, but you have to start the app in portrait mode before switching to landscape. Otherwise, the right side of the app is not active, basically the app still thinks the screen is in portrait mode and only the left side is active.
To duplicate the problem, exit the SRS Cmpcts app, dbl-click the home button, touch the SRS Cmpcts button in the task bar until you see the 'minus' sign, and then tap the minus sign. That kills the app. Now, start the app again with the iPad in landscape, and the right side of the app in no longer touch sensitive.