Well, here's where the problem with templates come in to effect!
I have absolutely no idea which template every line of code comes from! The ubbthreads.php is largely a mystery to me... (because of lack of tmpl documentation!)
I looked at the w3 page, it came up with a couple of hundred errors... none of which I understand... kept telling me that I hadn't closed off tags, followed by examples of my code, that clearly showed that I had closed off those tags... I don't get it.