This is friggin crazy. Over the past two weeks, my site moved up to #2 position for my primary keyword for 2 days (yeah!), then dropped off search results totally (boo!) for 2 days, then came back to #2 for three days (yeah!), and this morning dropped completely off the results again (crap!). I wish Google would stop all this fine-tuning and give us webmasters a chance to breathe.