julinho - 1:24 pm on Apr 26, 2012 (gmt 0)
I've seen this situation a few times: get a great link, see the rankings drop for a while, and eventually raise.
I am used to that, I don't follow rankings closely anymore, but I know it takes more than a few days to stabilize.
It probably takes a few weeks, possibly a few months (my opinion is that Google attempts to make this time frame unpredictable, otherwise it would be easy to tell how powerful a backlink really is).
Meanwhile, just keep working on your site.