I have imported a PowerPoint presentation from my Wintel machine, and it doesn't always advance when I tap or swipe the screen. When it is stuck, it won't go backwards either. The screen response seems fine as I type this message, and the instructional presentation acted fine. I can only get to thet next slide by double tapping to edit mode and choosing the next slide on the left index bar. Thet presentation is about 7 MB in 14 slides. I've removed all the animation I can find in the presentation (did that before I importing it). Can't think of what else to try.