SuzyUK - 9:44 pm on Jul 8, 2010 (gmt 0)
I think you're all reading way too much into it..
"where there's smoke there's fire" seems awfully relevant.
No, there's always been smoke (CSS type smoke that is) but it never ganined the fire analogy until it started breathing Google/SEO Fire, tedster is absolutely right, the OP is likely to be somewhat of a difference, maybe the site wide change/"penalty" is nothing to with CSS - but the mere fact that it is a sitewide code change, HTML, CSS, Platform or otherwise, maybe a "wide boy" just took over a recently dodgy site (not saying you are flicky.. but just trying to make the analogy that none of us actually know the full story)
We have no way of knowing what else may actually be an affecting factor.. my next question has to be, for those that are able to get picky over which pages they (smugly?) change/or don't change is it because they know better - is it because they can actually tell us, with 100% proof, their reasons or is it because the "unaffected" changed page content didn't warrant a flag?, was it really anything to do with the styling (CSS is only a suggestive styling language remember!) and If it was, which ones are they and why are they "broke" as opposed to similarly HTML Source coded ones..
then..are you hand coding/tweaking/able to write php/html/css, I take it you're not using an open source CMS template where one change affects all pages and not just the ones you deem "broken"?
that I feel is the major issue - more contributory to the Shock 'n' Awe effect than actual CSS alone, - a wake up to a different technology, a change of software platform - what sets your site apart, are you "really" an authority or you are an pro/am, just slightly under the radar, where every change just might raise a flag - and I take it you expect the "hobby sites" to die a death after they've been unattended for a while? how do you think SE are going to figure that out without adding an auto pen for a site wide change?
every JoeSchmoe can use a CMS template, but how many of them know how to make it (or sections of it) different enough (from the orginal "unbroken" amateur site) to not raise that big red flag? - I honestly think it doesn't matter if you do it bit by bit or do it all in one go like the OP, I think it's gonna have a effect, much the same an plain old HTML tweaks - so at this point in time do you read all the ol' posts and sit back on your laurels or bite the bullet and work with the times? - my advice is to look at the big picture and decide what's better to keep up with for the skills/needs you have at this time