As a friendly advice, I’d say: Kill it! Let it burn in Hell!
Seriously tho, Y! Sitebuilder is EVIL. And I’m not talking goth-slash-my-wrists-while-listening-to-Cradle-of-Filth kind of evil, either.
It’s evil in the same way Micr$oft is evil – the results are not what you expect, it’s frustrating, and it has a lot of redundant code. I’ve tried making a site with that evil hellspawn service, and – omg surprise – it looked weird, the code was a nightmare, and it only worked acceptably in IE. Which is also evil, for very much the same reasons.
Personally, I’d say code the site either with Dreamweaver, or, ideally, by hand. Or send my money and data and I’ll do it (Valid XHTML and CSS are, or should be, Holy Grails for any coder)
If not, at least try CSS.
Drinking Lysol never hurt anyone…