error crateing mailbox under asp.net in c#

[niels hologa]

hello all,

I have different problems creating an exchange 2000 mailbox for an ads
user with c#. I have a domain controller and an exchange mailbox store
who are different and the iis is also another server. all three are in
the same ADS domain. The Home MDB string is entirely correct because
I've copied it directly from ADSIedit. I've also changed my web.config
to impersonate so that the script runs under a domain user. This user
has also the 'Act as part of the operating system' privilidges and the
administrator rights on the exchange server.
I thought I#ve made everything correct but I still get the following
error messages. Can anybody help???
<pre>
----------------------------------------------------
The following error occurs:

Exception Details: System.ArgumentException: The parameter is
incorrect.

Source Error:

An unhandled exception was generated during the execution of the
current web request. Information regarding the origin and location of
the exception can be identified using the exception stack trace below.

Stack Trace:

[ArgumentException: The parameter is incorrect.]
CDOEXM.IMailboxStore.CreateMailbox(String HomeMDBURL) +0
WebApplication2.WebForm1.Page_Load(Object sender, EventArgs e)
System.Web.UI.Control.OnLoad(EventArgs e) +67
System.Web.UI.Control.LoadRecursive() +29
System.Web.UI.Page.ProcessRequestMain() +724
------------------------------------------
This is my source code:

IADsUser objUser;
CDOEXM.IMailboxStore mailbox;
DirectoryEntry newuser =
de.Children.Add("CN="+Request.Form["displayname"],"User");

newuser.Properties["sAMAccountName"].Add(Request.Form["displayname"]);
newuser.Properties["userAccountControl"].Value=0x200;
newuser.CommitChanges();

objUser= (ActiveDs.IADsUser) newuser.NativeObject;
objUser.AccountDisabled=false;
objUser.SetInfo();
objUser.ChangePassword("","xxx");
objUser.FullName="Testing User";
newuser.CommitChanges();
objUser.SetInfo();

mailbox = (CDOEXM.IMailboxStore)objUser;
string homeMDB = "LDAP://ADCSERVER.DOMAIN.NET/CN=Mailbox Store
(EXCHANGE_STORE),CN=First Storage
Group,CN=InformationStore,CN=EXCHANGE_STORE,CN=Ser vers,CN=Administrative
Groups,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=DOMAIN,DC =NET";

mailbox.CreateMailbox(homeMDB);
objUser.SetInfo();
-----------------------------------
</pre>
thanks,

niels