ODBC Trusted_Connection Call To SQLGetInfo Returns DBO As User Name, Not NT User

Hello, all:
I am connecting to SQL Server 2000 with a trusted connection, and that is working fine. I then am issuing a SQLGetInfo call to find out the SQL_USER_NAME, which is always returning dbo instead of (my) Windows NT login name, which I expect to see. THe authentication is (apparently) confirmed by the SQL Server session monitor where it shows the right Windows NT user name logged in, over ODBC. With a standard SQL Login, untrusted, I definitely get the right user name back, not dbo.

So:

Login Type / user id /returned value from SQLGetInfo

Windows Authentication / Windows login / dbo
SQL Authentication / Windows login (UID) / UID

The problem is that I am trying to confirm that the userid entered in a dialog or passed on the command line to my application matches the actual connected user name inside SQL Server....


My questions:
Is there some pathology in Trusted_Connections that masks the Windows/NT login name and always returns UID 'dbo' from a call to SQLGetInfo? Is there a MSS (public) stored procedure that can robustly give back the logged in user name so I can bypass the SQLGetInfo call?