We had several 3 word phrases that we ranked between 1 and 4 at the end of the dance. We were really happy, things were well. One of our top results got nuked in a cache problem (we spat out PHP errors, eventually dropped in the rankings), and had a server outage last weekend.
We've had some outages this month, which we have fixed. However, since the problems (perhaps during Google's refreshing? We're a PR 8 site), we've dropped from spots 1-4 to 11-14. A few spots I'd figure is the normal shuffling, but a nearly across the board 10 spot drop?
I have two theories. One is that our IA structure designed to help users navigate is triggering duplicate filtering (we tried to engineer around that, but we may need to hurt our navigation to help our Google positioning) and penalties, penalties added post dance. The second theory is that Google saw the downtime and knocked us down a notch. Single Google doesn't care about fairness, just providing good results, trying to avoid results from an unreliable server makes sense.
My concern is that if we have penalties, I'd like to fix them ASAP and hope that they aren't final. If it is a short-term problem that will be fixed in 2 months from the downtime, I'm okay (and going to hire a full-time sysadmin/babysitter to prevent that from happening again). If it's a permenant penalty, I don't know what to do.
The site is in my profile, but looking at it may/may not help you understand the duplicate issues. Sticky me if you want to know what my concerns are.