danijelzi - 9:37 pm on Jun 7, 2011 (gmt 0)
I have a site hit by Panda in the same situation, index was in 20# position, now is on 11#. What changes did you made?
there were many changes, including removing some ad units, removing wordpress tags, and other things most pandalized webmasters did, but it looks like return of the index to #1 was caused by removing links to monthly archive pages. Maybe archive of the last month and index were considered as duplicates, which they actually are - both display the latest posts in the same way.