Multiple "User Registration" profiles only add to one group

Steps to reproduce on demo (tested for Drupal):

1. Create at least two profiles Used for "User Registration."
2. For each profile, select a different group under "Add new contacts to a Group."
3. Add a field to each profile, for example, a simple checkbox field.
4. When a user registers, the only possible group addiditon is for the highest weighted profile. Other groups selected at (2) above are ignored.