Impersonation from SQL Server to Exchange linked server

Hi, im tryin to get IMPERSONATION to work between SQL Server 2005 and
Exchange 2007 via ExoleDb (Microsoft Exchange OleDb provider)
The two servers are in the same box (Running Windows Server 2003), the user
can impersonate Exchange accounts (its the same user that i use for EWS and
impersonation works for him accessing Exchange Web Services)

The linked server is created with this:

EXEC master.dbo.sp_addlinkedserver @server = N'exchange1',
@srvproduct=N'Exchange OLE DB provider', @provider=N'exoledb.DataSource.1',
@datasrc=N'file://./backofficestorage/ex2007.local/MBX/testuser01'

I tried all the posible "sp_addlinkedsrvlogin" combinations (thats not the
problem) .

When i make queries the following error is shown in SQL Managment Studio:

OLE DB provider "Exoledb.DataSource" for linked server "Exchange1" returned
message "Could not impersonate the user. COM security must be setup to allow
'IMPERSONATE' access.".

When i try the server connection the following message is displayed:

Cannot connect using OLE DB provider "Exoledb.DataSource" to linked server
"EXCHANGE1". Verify the connection parameters or login credentials associated
with this linked server.
OLE DB provider "Exoledb.DataSource" for linked server "EXCHANGE1" returned
message "Could not impersonate the user. COM security must be setup to allow
'IMPERSONATE' access.". (.Net SqlClient Data Provider)

Server Name: DEVEX2K7-EXCH
Error Number: 7304
Severity: 16
State: 2
Procedure: sp_testlinkedserver
Line Number: 1

Some of the things i have tried (with no luck) are the following:

* Set the server for "Trusted for delegation"
* Set the user account to "Account is trusted for delegation"
* Check that the user i'm trying to impersonate have not checked the "Account
is sensitive and cannot be delegated"
* Set the component services computer default impersonation level to
"Delegate"

I don´t know what i'm missing, any help will be grateful.