Updating profile fields via user.save

So if I create a new user via xmlrpc and the services module I can populate profile fields no problem using user.save, but for some reason I cannot update profile fields using user.save I'm actually connecting to xmlrpc from java.

I've done it in php as well.

$user_object = array(
'name' => 'test_user_from_api',
'profile_name' => 'James',
'profile_last_name' => 'Test',
'pass' => 'testuser',
'mail' => 'james@yahoo.com',
'status' => 1
);

if I pass this user_object to user.save it will create a new user, but after if I specify the user's uid so it tells it to do an update of this user's record, it will update everything successfully (if I make some changes) except for the profile_last_name and profile_name fields (which are the user's last name and first name respectively).

Anybody already run into this? If a Woman changes her last name (as a for instance) after getting married, I cannot do updates to the profile field for her lastname to be updated. Before I start coding my own version of user.save I want to see if anyone has encountered this already.

Thanks