Image paths changed -- how to correct?

On our site the path to images has changed or reverted to IP addresses instead of domain names. Where can I go to change this configuration? I looked in config.php and was unable to find anything related to the image path.

We are using: ExpressionEngine Core Core v2.5.5 - Build Date: 20121220

In our template for site/news: img src=”{news_photo:summary}” alt=”Image paths changed – how to correct? “

And it outputs: img src=”http://ip-address/~user/path/path/uploads/image.jpg” Where do I change the ip-address to use the fully qualified domain name?

This changed out of the blue – as far as we know, nothing has been changed on the backend, so we’re stuck on where to look.

Thank you!

Brad