I've already posted in another thread that it appears that only scrapped pages of my site are affected by Panda.
First, my category pages: not scrapped, have decent raking.
Second, my older posts: not scrapped, have decent ranking.
Their rankings dropped a bit, but it looks like it's only a side effect of the fall of pages that were scrapped.
Also, checked my competition sites - same thing
scrapped = drop
not scrapped = ok.