Uninstalling 7.x-4.x-dev doesn't work perfectly. I get the following error message:

PDOException: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'user_badge-1-0-0-und' for key 'PRIMARY': INSERT INTO {field_data_field_user_badge_text} (entity_type, entity_id, revision_id, bundle, delta, language, field_user_badge_text_value, field_user_badge_text_format) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array ( [:db_insert_placeholder_0] => user_badge [:db_insert_placeholder_1] => 1 [:db_insert_placeholder_2] => 1 [:db_insert_placeholder_3] => user_badge [:db_insert_placeholder_4] => 0 [:db_insert_placeholder_5] => und [:db_insert_placeholder_6] => Administrator [:db_insert_placeholder_7] => ) in field_sql_storage_field_storage_write() (line 494 of /home/mysite/public_html/modules/field/modules/field_sql_storage/field_sql_storage.module).

Here's how to reproduce it:

A) Install 7.x-4.x-dev and add a user badge.
B) Disable & uninstall module.
C) Reinstall module and try adding the same exact user badge from step #A.

So basically I have to manually delete this from the database for now.