Profile form validation in Drupal User Registration - form values are alternately returned from multiple submits

When a Profile is embedded in a Drupal form (e.g. user registration) - and a form validation error is triggered - the profile field inputs are returned in an alternate sequence if you submit the form multiple times. I recreated on 3.0 and 3.1 - steps with sample data setup (and Name / Address profile in user reg):

Go to user reg and submit with all fields empty.
Now enter 'Dave1' as first name and submit - form comes back w/ first name empty
Now enter 'Dave2' as first name and submti - form comes back w/ 'Dave1' in first name

If you keep submitting - first name value will alternate between Dave1 and Dave2.

Not sure what's happening in the session - but seems like this could cause user errors and frustration - since submitted values are not returned properly.