Using the Twenty Ten theme and wp-admin in Chrome/FF/IE. (Tried all of them with the same issue.)
Twenty Ten supports only one menu. In the last few weeks, something odd started happening. When I edit my menu and save the changes, the Menus > Manage Locations > Primary Navigation menu loses the menu selection, so when I refresh the web site, I see a scary listing of all top level pages going across the menu bar. Then I have to go reset this option back to my one and only menu and save it, and when I refresh the site, it loads normally again. I go through this drill every time I need to make changes to the menu.
Starting today, when I edit my menu, the changes are not being saved. (I mysteriously lost a bunch of menu items at the end of the menu.) I'm trying to put them back where they were, but WP is not saving my menu edits.
As of today, I'm dealing with both issues and not sure why. Any insight here?