This throws me off now and then. I quickly create a database in EnterpriseManager then run a script to create objects using Query Analyzer. Since I can to log in as 'sa', everything seems fine -- but I can't log in using a connection string even though 'sa' *should* be the dbo for the database. so what's going on? there's a catch.
I actually wasn't paying attention when I registered the server in Enterprise Manager (rare - but it happens). So, Instead of using SQL Server authentication, it was set for windows authentication.
Hence, the database was created by the windows user, not 'sa' -- therefore the dbo was *not* sa. if i bothered to look in the system tables, that'd be pretty obvious.
Once you straight out the dbo, the connection string should work as expected.