can't save revision of field

when field attached bundle type of entity, it can't save field's revision. It's just save new field's revision.

Example: i'm using module profile2
1 - Create profile type is: test_new
2 - Add new field (with name: profile2_field1) for this with type is text.
3 - Open http://localhost/drupal7/profile-test_new and input values for this. with link: http://localhost/drupal7/profile-test_new/1/edit
4 - Edit info of 3.
5 - Open phpmyadmin and view data of table field_revision_field_profile2_field1, It's just save new field's revision.