tedster - 3:02 pm on Jun 23, 2011 (gmt 0)
Quite often, if Google sees a problem with their guidelines you will see a message in your WMGT account about the problem. If they feel you are just plain up to no good, they might not send a message.
If you know of a violation on your site, fix it and send a Reconsideration Request. If there is a manual penalty, it might be lifted. If there is no manual penalty, they often will tell you that.