Slider shows blank slide randomly

We recently used your plugin on a client site, and overall it’s been great. The only issue I’ve found is that it randomly shows a blank slide instead of cycling to the next post. We’ve noticed the issue on an iPad, and we’ve been able to recreate it occasionally when we resize the browser in Chrome, however that doesn’t always cause the issue either. Like I said – it’s very random.

You’ll see the slider near the bottom of the home page here: http://www.principiaconsulting.com/

Here’s a screenshot of the slider on an iPad
http://gmm.to/1Px9n5o

Any ideas on what the issue might be here?
Thanks!

https://wordpress.org/plugins/recent-posts-slider/