Have to click back button twice

For about a month or so when i'm reading I have to click the back button twice. When I checked my history it has the page I'm on and above it on the list is the thumbnail page. It's been pissing me off, any ideas on how to fix it. Also it doesn't happen on my phone or computer, only my Kindle Fire. And it's only when I click on the page, it doesn't happen when i click the next button

I'll take a look and see what's going on, we'll be rolling out a new online reader soon that should fix issues like this.