ldap_add: Operations error

["Zamangoer, Ferruh" <ferruh.zamangoer@materna.de>]

Hi All,

i'am a absolute beginner in LDAP . I want to create  a test Database with
ldapadd . Yesterday the command ldapadd works sucessfully . Then I have make
some changes to slapd.conf and nothing works . Then I bring the slapd.conf
to the old settings following error occurs:  

adding new entry "o=iqdoq"
ldap_add: Operations error

ldif_record() =1 

can anybody help me what can I do or what's wrong in my Configuration or DB
?

thanks in advance

Regards 
Ferruh Zamangoer