Connect to sql server 2008 via DLL

Am using a connection string to connect to SQL Server 2000 via Visual Basic DLL. We are moving to SQL Server 2008. Tried to use same connection string but am not getting any results. Do I need to use a different string ?

I have tried these two so far w/no luck:

"DRIVER={SQL Server}; SERVER=ip.address; Trusted_Connection=no; DATABASE=newdb; UID=userid; PWD=pw;"