There are two possible authentication modes for the DB Engine: Windows Authentication mode and mixed mode. A trusted connection (Server=myServerAddress;Database=myDataBase;Trusted_Connection=True;)is the same thing as using Windows Authentication.
SQL Server can also use its own logins, such as the sa user. These are both authenticated and authorized by SQL Server. They are only viable if SQL Server is run in Mixed Authentication Mode. So... idk but try to verify this, it can be the cause of the problem.
Hope it helps.