5503landis - 2:28 pm on Mar 31, 2010 (gmt 0)
mm666 - I would concur with b-hood of the LAN in the fact that a couple of days isn't a big deal.
However, you need to think: (1) did you try some type of "trick" to try to boost your site ranking?; (2) is your site relatively new...less than 3 months old?; (3) did you do something to your benign thing to your site prior like chenged the meta information, moved major content around?
If none of the above, than wait a little bit more time before you get too concerned. I had a site that was doing great and then voila, it went from page 3 to page 10 overnight. A few days later it came back to page 3 but then repeated this cycle for about 3 weeks. For the life of me I couldn't explain why this was happening, but eventually it sorted itself out and the site's ranking is stable and moving onwards and upwards.