There is a bug in Talend Open Studio for Data Integration version 5.1.1 when adding a database connection. It has to do with the jdts component used for Microsoft SQL Server connections. When adding a new connection you may get one of the following errors:
The above error usually appears the first time you hit the button to “Check” the connection. The second and subsequent attempts will produce a different error message as follows:
This is a bug in Talend Open Studio for Data Integration that has a fix already implemented in the future 5.1.2 version.
See details of this bug at: TDI-21382 SQL Server Connexion Fail
Update on 3/5/2013: The Impossible to Initialize the Connection error has been corrected in a future version. Check out Talend Impossible to Initialize the Connection.