Pages missing from admin

I moved my wordpress installation from one hosting account to another. I copied the root folder from one account to the other and imported the database to the new account.

1. When I am not logged in to admin I can see all the pages.

2. When I log in some of the pages disappear and the site seems to revert back to the way it was a week ago before I added the new pages.

Why would it be wanting to seemingly revert back and some of the pages and resent work go missing? I copied over the current root folder and the current database?

Any help would be most appreciated!