Why do I get "Disconnecting: bad client public DH value" from the SFTP server ?

[Eyvind Almqvist]

I am building some SFTP java services in Webmethods for Tele2 in Sweden. 
First I built them as methods in a Java class. Then it is no problem to 
logg in to the SFTP-server. 

But when I make a Webmethods java service based on this Java class, it is 
not possible to logg in. There are no error messages or exceptions from 
Java, but the application hangs on the 
"resolveFile" call. The  message from the SFTP-logg is "Disconnecting: bad 
client public DH value". What does this mean and what can I do to avoid 
it? Here is the code:

-------------------------------------------------------------------------------------------
String SloggedIn="false";
     FileObject baseFileObject=null;
     DefaultFileSystemManager fsManager=null;
 
 
        boolean loggedIn=false;
                try{
 
                 fsManager = new DefaultFileSystemManager(); 
                fsManager.addProvider("sftp",new SftpFileProvider());
                fsManager.init();
 
                FileSystemOptions fsOpt = new FileSystemOptions();  
 
 
                SftpFileSystemConfigBuilder confB = 
SftpFileSystemConfigBuilder.getInstance(); 
 
                confB.setStrictHostKeyChecking(fsOpt, "no"); 
                confB.setTimeout(fsOpt, new Integer(timeout));
 
 
                        String 
uri="sftp://"+username+":rullgardin10@"+host+":"+port;

                        System.out.println("uri "+uri); 

baseFileObject = fsManager.resolveFile( uri, fsOpt );