Google Bugs & Accessibility

What are your thoughts on this...

We were ranked in the top 10 on google for all our chosen search terms.

Last week for no apparent reason we dropped to the 6th page.

After looking round for a reason we discovered that we had probably been penalised for something.

What we think we had been penalised for is in fact CSS hiding text on a page. Now this is entirely for legitimate reasons (displaying text instead of images should someone choose to turn of the styles etc) but it seems google cannot tell the difference between CSS hiding text for legit reasons and hiding text for keyword spamming.

This blog has quite a lot about it (the guy works for google)

http://www.mattcutts.com/blog/

What are other peoples thoughts on the fact that google appears to have a bug that is hindering accessible design?

It's definitly not a good thing but i'm sure google must be aware about it? Have you contacted them? Also are you sure this is the reason why you've dropped to the 6th page? It could be because of any number of factors such as the recent PR update.

I would be very surprised if making text elements to display:none unless images replace it, would affect Google rankings. There are some distinct image replacement css codes that are used for very certain reasons, as you say yours is to show text if styles are turned off. This should not affect SERP.

Contact Google and see what they have to say, also research the rest of your site to check if this is the only factor in your SERP.

We have dropped from a PR5 to 4 for some reason.

We have emailed google but they aren't hugely helpful to be fair. It just seems to be the most likely factor.

We havent really changed much else and having kept quite a close eye on the other top ten results all those companies appear not to have moved