When creating configurations using the Configuration Converter it generates invalid configurations for URI matching:

Map\Uri:                
     dev: plain_site_user
     admin: plain_site_admin

The working format is:

Map\URI:                
     dev: plain_site_user
     admin: plain_site_admin

This is clearly shown in the documentation: https://doc.ez.no/display/EZP/Siteaccess+Matching

In addition it was fixed successfully manually in December 2013: http://share.ez.no/forums/ez-publish-5-platform/routing-issue-after-upgrading-from-2012.12-to-2013.11-solved