dickbaker - 9:59 pm on Sep 19, 2011 (gmt 0)

incidentally... my SERPs position has plummeted for a few phrases that are related to the rich-snippets, and i'm half-convinced that its because they contain hidden text (which is fairly normal for rich snippets). has anyone else seen the same?

You lost me with that. I was thinking that "rich snippets" would be content-rich paragraphs, sentences, etc. It must be something else. If so, what?