SAP JCo 3 - cannot connect to repository using custom destination

I'm working on a Java application that will connect to SAP, with the destination configuration coming from a file, and the user and password being entered at run time. I'm trying to implement this using the createCustomDestination() method on the JCoDestination.

Here is some sample code of how I am trying to do this. There is also a test.jcoDestination file that contains only the connection information; no user name, password, or client.

import com.sap.conn.jco.JCoCustomDestination;
import com.sap.conn.jco.JCoDestination;
import com.sap.conn.jco.JCoDestinationManager;
import com.sap.conn.jco.JCoException;
import com.sap.conn.jco.JCoRepository;
import com.sap.conn.jco.JCoCustomDestination.UserData;


public class Test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		try {
			JCoDestination destination = JCoDestinationManager.getDestination("test");
			JCoCustomDestination customDestination = destination.createCustomDestination();
			
			UserData userData = customDestination.getUserLogonData();
			
			System.console().printf("Enter client:");
			userData.setClient(System.console().readLine());
			
			System.console().printf("Enter user:");
			userData.setUser(System.console().readLine());
			
			System.console().printf("Enter password:");
			userData.setPassword(new String(System.console().readPassword()));
			
			System.console().printf("Enter language:");
			userData.setLanguage(System.console().readLine());
			
			// Try to connect - this works
			customDestination.ping();
			
			// Try to connect to the repository - this fails
			JCoRepository repository = customDestination.getRepository();
			
			
		} catch (JCoException e) {
			e.printStackTrace();
		}
		
	}

}

Everything works well down through the ping() call, which means the connection is being created. However, on the getRepository() call I get an exception saying that the client isn't specified. It's as if the getRepository method is ignoring the custom destination information I set and only looking at what's in the destination file.

Am I doing something wrong, or is this a bug in the JCo library?

Thanks,

Jonathan