Thanks Whoo for taking the time. Village-Idiot.org is amazing! I take it you're a professional? If not, I'm sure you should be. Those colours (orange - not red - and purple) are the New Theatre colours, so I'm stuck with them. I'm about to release an alternative stylesheet with different colours. (To see that piece of code in action, visit my other site, ttproductions.com, and click 'Pimp my Site.')
As for validity, it has always been valid, it's just that I only put the random photos in the sidebar this afternoon and widened the site from 720px to 800px to cope. This process proved harder than I'd imagined, and mistakes were made.
The marquee thing displays in Firefox's latest version on both Mac OS X, and Windows XP. I can't imagine why it didn't work for you.
One piece of constructive criticism for you: 'Hows the weather' should read 'How's the weather.' I'm an English Student at university, and a stickler for good grammar!