Unable to connect MS SQL Server 2005 named instance database

Hi,

We are trying to configure openfire 3.6.4 against MS SQL Server 2005 named instance (not to the default instance), however we are getting connection refused error or user is not associated with a trusted SQL Server Connection. However user is a windows user and he has dbowner permission against the SQL Server named instnace database.

The URL which we trying is

jdbc:jtds:sqlserver://[host-name:port]/Openfire;instanceName=ABC

User name: <username>

Password:

PS: The database name is Openfire and SQL Server db instance name is ABC

Could you please suggest whether we need to check any specific driver? Coz we are able to connect SQL server through other applications.

Thanks in advance.

Yogesha