Active Directory user creation with python-ldap

[Nello]

I need to create an Active Directory user using python-ldap library.
So, I authenticate with an admin account and I use "add_s" to create
the user.
Anyway, by default users are disabled on creation, and I can not set
userAccountControl to swith off the flag ACCOUNTDISABLE, i.e. setting
userAccountControl with 512 (NORMAL_ACCOUNT) value. See page
http://support.microsoft.com/kb/305144 for a complete list of
userAccount flags.

If I try, the server respond:
ldap.UNWILLING_TO_PERFORM: {'info': '0000052D: SvcErr: DSID-031A0FC0,
problem 5003 (WILL_NOT_PERFORM), data 0\n', 'desc': 'Server is
unwilling to perform'}

Same thing if - as someone suggests - I create the user without a
password and try to set userAccountCreation later.

This is the code I use to create the account.
Any suggestions?

----------------------------

import ldap
import ldap.modlist as modlist

def addUser(username, firstname, surname, email, password):
    """Create a new user in Active Directory"""
    ldap.set_option(ldap.OPT_REFERRALS, 0)

    # Open a connection
    l = ldap.initialize(AD_LDAP_URL)

    # Bind/authenticate with a user with apropriate rights to add
objects
    l.simple_bind_s(ADMIN_USER, ADMIN_PASSWORD)

    # The dn of our new entry/object
    dn="cn=%s,%s" % (username, AD_SEARCH_DN)

    displayName = '%s %s [%s]' % (surname, firstname, username)

    # A dict to help build the "body" of the object
    attrs = {}
    attrs['objectclass'] =
['top','person','organizationalPerson','user']
    attrs['cn'] = str(username)
    attrs['sAMAccountname'] = str(username)
    attrs['userPassword'] = str(password)
    attrs['givenName'] = str(firstname)
    attrs['sn'] = str(surname)
    attrs['displayName'] = str(displayName)
    attrs['userPrincipalName'] = "%s at mail.domain.it" % username

# Some flags for userAccountControl property
    SCRIPT = 1
    ACCOUNTDISABLE = 2
    HOMEDIR_REQUIRED = 8
    PASSWD_NOTREQD = 32
    NORMAL_ACCOUNT = 512
    DONT_EXPIRE_PASSWORD = 65536
    TRUSTED_FOR_DELEGATION = 524288
    PASSWORD_EXPIRED = 8388608

# this works!
    attrs['userAccountControl'] = str(NORMAL_ACCOUNT + ACCOUNTDISABLE)

# this does not work :-(
    attrs['userAccountControl'] = str(NORMAL_ACCOUNT)

    # Convert our dict to nice syntax for the add-function using
modlist-module
    ldif = modlist.addModlist(attrs)

    l.add_s(dn,ldif)