http://blogs.msdn.com/tejasr/archive/2008/06/19/resolution-moss-this-page-has-been-modified-since-you-opened-it-you-must-open-the-page-again.aspxBehavior/Symptoms: Whenever user tries to add a web part to the page, he gets the following error message "This Page has been modified since you opened it. You must open the page again." If he refreshes the page and adds, It works. User hasen-USCommunityServer 2.1 SP1 (Build: 61025.2)