Merge agent login problem

I have a push merge replication up and working in development SQL Server 2005 (publisher) and SQL Express (subscriber). Because the upgrade from 2000 to 2005 for our production servers has been delayed for who knows how long, I am working to set the same replication up with 2000 and MSDE.

The merge agent is failing in 2000 with the error:

Login failed for user '(null)'. Reason: Not associated with a trusted SQL Server connection. (Source: MSSQLServer, Error number: 18452)

The 2005 merge agent runs fine. I think it is because the 2005 subscription wizard allowed me to set the 'Run as: SQL Agent Service Account' option, instead of a windows authentication uid. There is no opportunity to set this in the 2000 subscription wizard nor on the merge agen job step itself. I didn't take a screen dump, but am confident that I used the SECURITYMODE=SQL parameter on the MSDE client install.

Any help on whether I'm correct on what the problem is and what to change to get the 2000 merge to log in with the SQL agent service account would be great. Thanks.

Is the SQL agent service account a windows account? If so, then you have to change the subscriber machine to allow windows authentication. SECURITYMODE=SQL means only sql server logins can connect. You should be able to use Enterprise Manager to change the subscriber's server properties to allow both SQL and Windows authentication mode.|||

The install document with MSDE 2000 says that SECURITYMODE=SQL enables mixed mode. The server shows Windows and SQL authentication enabled.

I've looked at the replication jobs with both Enterpise Manager and Management Studio and cannot see how and what the merge is trying to log in to the client with, except for the difference noted in my original post.

I also noticed that the program sqlmangr.exe fails when the MSDE PC is started. It seems to operate ok except for the merge connection, though.

|||The difference appears to be that 2005 can impersonate the service account and 2000 cannot. I added the publication server service account as a user with the same password on the subscription machine and the merge agent was able to log in.