Not sure if this is related, but on several of my sites, it seems that they have hit a wall.. 5000 pages indexed out of 20,000 or so. They are forums so the sites slowly grow over time, but seems to max out at about 5000 pages. Pages will drop from the index and newer pages will be added. I have tried everything to get all the pages indexed, but there seems to be that wall where G will only display so many of them and no more. What I found interesting is I changed the number of posts per page from 10 to 20 programmatically which actually cut down the forum pages to about half of what they originally were... same thing, about 5000 in the index of 10,000 pages with more content.