Google Prettify Removes Line Breaks?

When I try to use Google Prettify to syntax highlight my code, I notice that it causes code to become one line ... why is that? When I remvoe prettify, it works

This is a well-known issue that someone's still trying to track down. Hang on, I've got the bug favourited somewhere...

Yeah, there we go, here's the link to the issue in the Google Code issue tracker, assuming you're using IE, or one of the other affected browser/versions.