Viewing multiple pics in threads, something has changed for me

I used to be able to "click" and enlarge the pic, and now whenever I do that, the pic is opened in a new browser window.

Is it something I changed here, or something in my browser setting?

I'm using FireFox

Thanks

 

No problem here and I use Firefox. HRP

 

I changed to Comodo dragon, all works fine.

Funny, FF worked here, and still works on the Ford Barn.

Thanks