This issue involves most if not all of my blogs because I changed themes on all from “2010” to “Motion”. I found out first through Google Webmaster Tools that there is a large amount of 404 (Page Not Found) errors and I had no idea why! I have corrected a few but have many left to resolve. This is what I have found so far : many page/post revisions were lost in the transition to Motion. I would have to go down the list at least two to three revisions before I could find one that would have content and would appear in the editor. Some revisions would be visible in the HTML but not in the Visual tab! Also, The menu option has two choices for posts and pages: most popular and ALL, the most popular in the “pages” section does not include a “Home Page”. I have had to go back and change the menu to include a home page. I suggest that you include a home page in the most popular option. I am getting tired of having to learn “the hard way”. I still have many 404s to resolve so it’s back to work!