error with ldap_get_values_len()

[Smeagollum]

im trying to read mac addresses out of a novell edirectory dhcp server with php. the mac address is binary data so i cannot use the function ldap_get_entries().

when i use the function ldap_get_values_len() i get the following error:
Warning: ldap_get_values(): Cannot get the value(s) of attribute Decoding error in /var/ww...

here is my code:
[code]$ldap_result2=ldap_search($ldap,$base_dn,'objectClass=*',array('dnipmacaddress'));
$erster=ldap_first_entry($ldap,$ldap_result2 );
$mac=ldap_get_values($ldap,$next,'dnipmacaddress');[/code]