Can't do modificaton on slave server

[kdrjy <kdrjy@263.net>]

Hi:
  I have set up a master and slave ldap server successfully.But I found 
some strange case.
  When I do some modification on the master server,the slurpd will 
propagate it to slave server.But if I do the same modification on the
slave server with the same "binddn" and "userpassword",I always get 

"insufficient access".
I am sure I have set the properly ACL .Because 
When I shield the "updatedn" in the slave configure file and start
slapd as a stand alone deamon,I can do any modification successfully.
I don't know what on earth happened to me.
  Please give me some information.
  Thanks in advance for any help!