User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.2.1) Gecko/20021130 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.2.1) Gecko/20021130 I have verifiecd this in Netscape 7.01 and latest nightly builds. Once I remove all tabs from the sidebar, apply the changes and attempt to add new tabs to it from the right side of the "Customize Sidebar" dialog nothing happens. However, once I add a tab via a website like OSNEWS.COM installing it with XPI I can once againa dd tabs from the right side of the "Customize Sidebar" dialog. Reproducible: Always Steps to Reproduce: 1. Press F9 to open sidebar 2. Click tabs dropdown menu and click the "Customize Sidebar" entry. 3. Remove all tabs from the right side with the heading "tabs in sidebar". 4. Try adding tabs from the left side of the dialog with the heading "Available tabs". 5. If you do not have tabs get some from http://channel.netscape.com/sidebar/sbd/index.tmpl and repeat step 4 6. Now from a website like http://channel.netscape.com/sidebar/sbd/index.tmpl click one fo the tabs to install. You should now have that tab in your sidebar and you should be able to once again add tabs from your "available tabs" to the active tabs in the sidebar.
*** This bug has been marked as a duplicate of 135717 ***