adding first E2K TO E5.5 SITE

HI
During the installation of the first Exchange 2000 in Exchange 5.5
Site, I received the following error 0XC1030B0, when I checked the
log file of the Exchange 2000 setup I found the following.

[14:34:45] Sc_dra_replica_add
(K:\admin\src\libs\55dsinst\cdsinst.cxx:3929)
Error code 0XC1030B0C (2828): The distinguished name
already
exists. Try the operation again. If the error recurs, try stopping the
directory service and the Administrator program and then restarting
them.

And the installation is failed.
I checked Q255703 mentioned the same problem but there is no
solution for that.

Is someone ever solved this problem, because there is no answer in
all MSF.