Problems going "back" on Firefox?

I thought that the new update would fix it, but it hasn’t.

When I open a new tab (which I do a lot if I’m going to be clicking multiple links on the same page), everything seems normal. But then when I navigate to another page on the new tab, I can’t hit the “back” button to get back to the page I had originally opened in a new tab.

For example. I go to google images and open one of the pics in a new tab. I click “full size image” to see what it looks like bigger. But then I can’t press ‘back’... I have to either re-enter the URL to google images or close the tab and open it again in the original window.

I googled “can’t go back on Firefox” but the top results were all from 2008.

Am I the only one experiencing this problem?