I have the same issue. I contacted the developer on March 27th and this was his response:
“We are aware of this problem and we hope to have a fix for it released in the next few days. We think it may be something to do with the W3 cache plugin because we cannot reproduce the problem on our own servers, we can’t see any obvious errors in our code and we know the problem is not consistent.
I don’t have a problem with [webpage] – it works as expected for me but I know that if I try reloading enough times, I’ll get to see the problem.
Whatever the cause is, we should have it fixed soon.”