Unable to change Navigation Settings

Error message from ULS log when trying to modify Navigation Settings (Site Settings > Navigation):

Unable to retrieve TopNavigationBar SPNavigationNodeCollection from Web at: <url>. The SPNavigation store is likely corrupt.

Run the following db script:

INSERT INTO [Cotent_db].[dbo].[NavNodes]
 ([SiteId], [WebId], [Eid], [EidParent], [NumChildren], [RankChild],[ElementType], [Url],
 [DocId], [Name], [DateLastModified], [NodeMetainfo], [NonNavPage], [NavSequence], [ChildOfSequence])
SELECT DISTINCT SiteId, WebId ,1002 ,0 ,0 ,1 ,1 ,'', NULL, 'SharePoint Top Navbar',getdate() ,NULL ,0 ,1 ,0
 FROM [Cotent_db].[dbo].[NavNodes] WHERE WebId NOT IN (SELECT WebId FROM [Cotent_db].[dbo].[NavNodes] WHERE Eid = 1002) 

Thanks to:
http://bimoss.wordpress.com/2009/09/29/unable-to-modify-global-navigation-add-headinglink/