I have seen it before but never really thoiught about it, but when I click on the Cache link in the search result, I can see a hit in my stats on that page which it shouldn't if it is cached, right? Another thing I saw the other day is that I updated my site (css.file) and then I clicked on a Cach link again and there was the new background.... Again, shouldn't it have been the old background? Somehow I think Google is having a problem with a mix of "not so cached pages" and Cached pages in their index and that they think that they have 2 pages and we get slammed with a duplicate content and get supplemental... I have been checking a lot of Cached pages and even if it says that they were cached in August last year, it is a new pages/new background that shows up. Maybe I am just dumb, but isn't a Cached paged saved in their Cache server??
The HTML page is cached, but the stylesheets are not. It could have to do with how you implement stylesheets, but my stylesheets never seem to be cached. It's a problem when I try to check out sites that are overloaded, because anything defined within <HEAD> tags has to be downloaded before the page will load.