callbacks does not work in custom login module

Hi,

We are upgrading portal from 7.01 to 7.31. I am working on custom login module.

I am using NameCallBack, PasswordCallback and httpcallback  (prior to upgrade used webCallback which is deprecated in 7.31)

All these three callbacks works fine in our sandbox which uses Portal Database as UME, But same code fails and returns NULL for callbacks in Dev system where we use Active Directory.

//In initialize(Subject subject, CallbackHandler callbackHandler, Map sharedState, Map options)

super.initialize(subject, callbackHandler, sharedState, options);

this.callbackHandler = callbackHandler;

// in logion()

NameCallback nameCallback = new NameCallback("User name: ");

PasswordCallback passwordCallback = new PasswordCallback("Password: ", true);

try

  {

  callbackHandler.handle(new Callback[] { nameCallback, passwordCallback });

  }

Any ideas will be appreciated.

Thanks,

Dileep