It seems Opera's not respecting something with the CSS. The content area not only has a minimum height, but the pre has auto overflows (meaning it should force the box to only a given size and then use scrollbars).
Given that the browser with 80% to 90% can't handle XHTML properly, and after long drawn out debates in usenet over the best doctype, I've personally settled on HTML 4.01 Strict. Once I discovered how IE actually handles XHTML, that sealed the deal.
Got it back up after a brief stint of being incredibly stupid.
One thing I'd really like to get happening is fully-fledged Markdown support, which'd benefit everyone. Anyone who wants to jump in is more than welcome to.