For migrate your users from XOOPS 2.2.x version to 2.0.x version, you can use this queries :
1)With phpmyadmin, truncate your x2014_users table, after execute this query
insert into `x2014_users` (`uid`, `name`, `uname`, `email`, `url`, `user_avatar`, `user_regdate`, `user_icq`, `user_from`, `user_sig`, `user_viewemail`, `actkey`, `user_aim`, `user_yim`, `user_msnm`, `pass`, `posts`, `attachsig`, `rank`, `level`, `theme`, `timezone_offset`, `last_login`, `umode`, `uorder`, `notify_method`, `notify_mode`, `user_occ`, `bio`, `user_intrest`, `user_mailok` )
select `uid`, `name`, `uname`, `email`, `url`, `user_avatar`, `user_regdate`, `user_icq`, `user_from`, `user_sig`, `user_viewemail`, `actkey`, `user_aim`, `user_yim`, `user_msnm`, `pass`, `posts`, `attachsig`, `rank`, `level`, `theme`, `timezone_offset`, `last_login`, `umode`, `uorder`, `notify_method`, `notify_mode`, `user_occ`, `bio`, `user_intrest`, `user_mailok` from x22x_users left join x22x_user_profile on x22x_users.uid=x22x_user_profile.profileid;
(*)The tables must be in the same data base with different prefixes. To adapt the prefixes given in example to your situation
2)recreate your groups
insert into x2014_groups (groupid, name, description, group_type)
SELECT groupid, name, description, group_type FROM x22x_groups` WHERE groupid >3;
3) Affect your users in the groups
insert into x2014_groups_users_link (groupid, uid)
SELECT groupid, uid FROM x22x_groups_users_link;
