wp_update_user clearing data in wp_usermeta when called to change user password

I’m using the Register Plus Redux plugin with custom forms/pages for registration, updating your profile, and changing your password.

Everything is working super. One issue on the change password page:

– user is requested to enter their new password twice
– separate js verifies passwords match
– form posts to a script with with current user ID (from get_userdata() and the new password
– script updates password only with a call to wp_update_user using an array, $userdata, that contains just the user ID and the new password
– password is sucessfully changed

Here’s the rub, after changing the password, the info for that user ID in wp_usermeta is removed. The keys are still there (if they were set) in wp_usermeta, but the values are wiped.

I’ve verified that the call to wp_update_user is just sending the user ID and password, but I can’t figure out why this is happening.

Is this expected? is there a better way to do this?

TIA!