Plan_D - 8:49 am on May 23, 2010 (gmt 0)
I'm finding that pages that used to rank on the first page have actually disappeared from the index. These have been replaced by pages further down in that section.
For example if I have a long article running to 5 pages, page 1 used to rank very well for it's key words. But has now disappeared so I can now only find page 5 (this is now ranked 200+ in the serps though). This is because all the in-site links are to page 1 and probably any links from outside as well. Pages 2 to 5 also link to page 1.
I can't see any logical reason why google would rather index page 5 than page 1. So I am hoping that page 1 will reappear at some point soon.