Took me a while to work out what your problem was.

The issue I'm seeing is that if you click on an image in the product's image carousel to magnify it, you can't return to the product's page without using the browser's back button and the 'forward' and 'back' widgets aren't available. It isn't a browser specific issue, it occurs on Opera as well.

These aren't functions I use frequently, so you might get a quicker resolution by raising a support ticket with this added detail.