To answer your first question, 5.0 is the latest version of the SQL Toolkit but there is a new toolkit called Database Connectivity Toolset. I don't have it yet but I do know that there is cost to upgrade.
To answer your second question, error 4149 is created by Connect.vi and the error message says "Connect - Data source name not specified." I don't know if _SQLCIN.vi will generate the same error code. Without seeing your VI and your database, its hard to say any more. Double check your datasource name, connection parameters, and verify that you have the priveleges you need. Good Luck.