Each webmaster decides how to display an image. When you say "click A picture" it's kind of hard to imagine where you were when this happened. It could be the website you were visiting that changed their code. Anyway. Be more precise if you need help. And if you had an extension that was "fixing" something you didn't like in the way most websites function. And if this extension isn't compatible anymore then you'll have to contact the guy who did it. And see if he's ever going to change a few lines of code to get it compatible with the new Firefox version. I don't see how this is a firefox related thing honestly ;) Every problem coming from extensions not compatible anymore is to be reported to the extension's programmer.

The problem is the pictures now display centered with a black background or border. There was an addon that solved the problem in older firefox revs but it is not compatible with the new version. This is true for any jpg not just off the web. I do not know why the default has this. There must be a way to display only the jpg without the background/border that firefox puts on it.