Vaildation fails silently on required fields (Drupal user editing)

Replicated on demo sites 4.4 and 4.6, see attached.

On the demo site the default user demo does not have first or last name. Try editing the user in Drupal. Just enter first name, leave last name out, and save.

The system reports the data was saved, but does not save the data. Using edit profile seems to work correctly. The system warns that a field is a required field.