If you have valid privileges to your SharePoint environment, but still receiving this error "The Sever sent HTTP status code 401: Unuathorized" then the problem is likely due to MetaVis authentication methodology.
If the workstation on which MetaVis is installed on is logged into a valid domain, the application automatically picks up these credentials and tries to log in. However, if this account does not have sufficient privileges the "Unauthoried" error is shown. There are several work-arounds:
1) Re-start MetaVis under "Run As" - Hold down the shift key and click with your mouse on the MetaVis shortcut. Select Run As and type in either the admin account or any other account that has no rights to the SharePoint environment. If you do the later, you will be prompted to enter credentials when connecting to SharePoint.
See these Resources for further information:
http://support.microsoft.com/kb/294676
2) Relogin into the computer with a local account or a domain account with no SharePoint privileges. You will be prompted to enter credentials when connecting to SharePoint.