Login failed for give user id

I tried to create a mining model from a remote SQL 2000 database using local user id of remote server. Whenver I try to process the model I am getting login failed error. But the same model runs fine when I configure datasource using windows credentials.I found out the reason, when I set the impersonation mode to service account/degfault its working. But when I set to specific user name and password, its not working. Can somebody suggest me the possible cause.|||I found answer myself. I just created a local user and a role in analysis service database mapping to local user and granted him appropriate rights. Now I can process the data model under "impersonate particular user mode"