Reproduce: View any issue in firefox.

As you can see, the long lines in issues and comments break out from the bounding area of the left_column div.

I would suggest using white-space: pre-wrap, as it also preserves the whitespaces, but it would break lines too long.

The backside is that IE6 and older browsers will probably not preserve white-spaces this way.

In the end I wanted to write a long line, so anyone watching this issue in firefox could see what I have meant by lines not breaking. This text supposed to extend through the "right sidebar" in firefox. Since the design is not responsive this should be enough.