--- C:\Documents and Settings\William\My Documents\plugins.py-orig 
+++ C:\Documents and Settings\William\My Documents\plugins.py-flatten 
@@ -184,9 +199,16 @@
         try:
             environ['repoze.who.logger'].debug('LDAP-MD in for loop.')
             for (dn, attributes) in self.ldap_connection.search_s(*args):
+                # Flatten single-element lists.
+                for k in attributes.keys():
+                    if len(attributes[k]) == 1:
+                        attributes[k] = attributes[k][0]
+                        
                 environ['repoze.who.logger'].debug('LDAP-MD updating: %s.' % attributes)
                 identity.update(attributes)
+                
             environ['repoze.who.logger'].debug('LDAP-MD done.')
+            
         except ldap.LDAPError, msg:
             environ['repoze.who.logger'].warn('Cannot add metadata: %s' % \
                                               msg)