Here are som articles that describe it but the last one is pretty definitive in the few steps that it will take to fix this. This error is clearly a problem with permissions, it is making sure that you know which user needs these permissions.
http://databases.aspfaq.com/database/how-do-i-solve-operation-must-use-an-updateable-query-errors.htmlhttp://support.microsoft.com/kb/830977http://www.mikesdotnetting.com/Article/74/Solving-the-Operation-Must-Use-An-Updateable-Query-error