VB 5 datamanager - not allowing password to be set

[veena]

We are trying to add users to VBulletin 5.1.0 using the datamanager APIs.

The call fails when we try to set password in the datamanager object.

These 2 lines work :
$this->userdm->set('username', $username);
$this->userdm->set('email', $email);

The call crashes here:
$this->userdm->set('password', $password);

Here password is a clear text password.

This was working in VB 4.x but is not working after we upgraded to VB 5.1.0 today.

Why the call to set password in the DM object crashing?
What has changed in VB 5.0? Should the password be set differently in the object being sync'd to VB ?

Please help asap.

Thanks,
Veena