Yep. It worked fine in 2.0.0.7 on linux (that's what we used during devel), and then Firefox released 2.0.0.8, which regressed a bit, and reintroduced an old Firefox bug. There was uproar (we weren't the only site that looked bad in 2.0.0.8) and the Firefox team expedited the release of 2.0.0.9, and the site looks great again.

We actually held off on the announcement until 2.0.0.9 was ut!

So: consider upgrading Firefox right now, and give it another shot!

Problem is that Ubuntu hasn't updated Firefox to 2.0.0.9 in the repositories yet.