flanok - 10:43 am on Jul 7, 2011 (gmt 0)
This is also my theory, lost backlinks.
I mentioned this in another Panda thread, but no-one answered my post.
Around a third of my pages have lost their cache:
I get his message.
"Your search (ETC.) Did not match any documents" when I click on the cache link for pages within my site.
I believe this means I have also lost around a third of my internal backlinks.
When I then do the same exercise for other sites that link to me, I get similar stats.
In short, a huge amount of pages are still indexed in Google (title tags, desciption tags, urls only) but no content cached, so I guess the links that were counted from those pages are no longer being counted.
My site has not plumeted, just lost 4 or 5 places per page, again suggesting there is no penalty, more that I have lost some of the gains this year from incresed backlinks.
I hope that in time, these pages will be re-cached and links counted again, but I do wonder why it is taking such a long time or it could be that removing the cache of a page is the penalty.
I still wait to see.