[AccessD] OT: MS SQL question

Sorry for the OT but I am having a bad MS SQL day and responses have been
slow on the other list.

I have always designed my MS SQL with Windows Authentication and when
Anonymous access was required it was through IIS... for the last 10 years.

Now there is a new challenge. Connect MS SQL 2005 through MS SQL or 'sa'
mode and the server is proving a worthy opponent. 

The server is set to support both connection modes but I am not sure whether
these setting can be set/unset at the database level. I have created a user
and the system seems happy but when testing the connection through ODBC it
responds with something like:

Connection failed:
SQLState: '42000'
SQL Server Error: 4064
[Microsoft][ODBC SQL Server Driver][SQL Server]Cannot open user default
database. Login failed.

I am sure the issues is something very simple but after 2 days no joy.

Any insights?

TIA
Jim