SEO question
 

Do se's give a rats ass about valid html / xhtml?

i guess they don't care as long as they can parse it correctly

Not so much from what I've seen.

They should. :)

It becomes more and more important.

simple answer: yes

complicated answer: it depends

I have never noticed se's paying attention to how well I code

Yes. Take the two seconds to run your pages through a html validator.

well

if they can read it properly they don't care much....

look at your cache and see if it looks like it should

You can't go wrong by having good compliant code.. so why not take an extra min on the page to run it via validator and make it compliant?

I like designing my new sites using valid xhtml simply because there's less code between the bot and my content. As long as it's readable then I don't think it's a biggie since google.com doens't even validate.