website is not showing up on search engine results anymore

keywords that site was normally showing up for are now not findable on SE

[stinky]

I was ranking in top spots on google and yahoo for about 10 keywords for over 3 months already. Today i checked and my site is no where to be found for any of my keywords. I am thinking a got kicked off google and yahoo, but am not sure why, because the site is pretty clean. Here is the weird part, if i do a search on both SE for just my site name i show up in the results.
Questions:
Any one have any idea why this happened to the site?
I think I have a clean site, but was I flagged for spamming? If so, why would my site show up if I search just the URL?
What do I do now, should I email google?
Any advise would be greatly appreciated, thank you.

[skipfactor]

Hi Stinky,
A lot of sites seem to have had their index pages missplaced with this update. It's a long one, but read through the update thread & you'll find you aren't alone:

[webmasterworld.com...]