Hi Marco,
As Alex has said he has experienced a similar issue. There are 2 issues going on here. The majority of the time they can be fixed by changing the Exadsi loggin to the domain account, unfortunately this did not work in for Alex, but I would like to try it for you.
depending on the SQL version you are running you will find the Exadsi
in MSSQL 2005 you can find it here
Run MS SQL Server Management Studio
Open the tree view to your SQL Server
Open "Server Objects", "Linked Servers", "Providers"
In MSSQL 2000
Run MSSQL enterprise manager
In Security, Linked Servers Exadsi.
For both, please change the remote login to the admin account.
REgards
Richard
Richard Rae
Exclaimer Support