about case-sensitive

["人文钟"<cron@citiz.net>]

Hello everyone , I'm a freshman of ldap, we're working for applications that authorizating the user by LDAP, we have a "uid" of "teacher", but the users can login by name of "Cron" or "CRon" or something. So I must change the LDAP configuration so that the username can be case-sensitive. 
     so I follow some article like http://www.openldap.org/lists/openldap-software/200211/msg00328.html , but when I change my school.schema by that method of changing the "caseIgnoreMatch" to "caseExactIA5Match" or "caseExactIA5SubstringsMatch"

my school.schema
--------------------------------------------------------------
attributetype (1.1.2.1.3
      NAME 'teacher'
      DESC 'REFC1274:teacher of classroom eschool'
      EQUALITY caseIgnoreMatch  #        case insensitive
      SUBSTR caseIgnoreSubstringsMatch #    case insensitive 
      SYNTAX 1.3.6.1.4.1.1466.115.121.1.15{32768}) 

changing by follow .......

attributetype (1.1.2.1.3
      NAME 'teacher'
      DESC 'REFC1274:teacher of classroom eschool'
      QUALITY caseExactMatch
      SUBSTR caseExactSubstringsMatch
      SYNTAX 1.3.6.1.4.1.1466.115.121.1.15{32768}) 

or by follow.....

attributetype (1.1.2.1.3
      NAME 'teacher'
      DESC 'REFC1274:teacher of classroom eschool'
      QUALITY caseExactIA5Match
      SUBSTR caseExactIA5SubstringsMatch
      SYNTAX 1.3.6.1.4.1.1466.115.121.1.26{32768})

--------------------------------------------------------------
then I restart the slapd services, but that doesn't work

I have used the software of "Softerra LDAP Browser 2.5.3" to browser the LDAP entries and attributes,and see the "teacher's name" is "value" other than "attributes", can anybody help me to solve that problem?