I am using the following versions:
Joomla: 1.7.0
CB:1.7
CB Group Jive:2.4RC

I created a custom field named cb_sharegroup of type multiple select. For user Ruut2 the value of this field is "CATO2, Ecofys". I created two auto rules. Rule 1:
Triggers:onDuringLogin
User:automatic
Access: Manager, Administrator,Registered, Author, Editor, Publisher, Super Users
Confition: cb_sharegroup / Does Contain / Ecofys
Auto: Join Groups
Groups: Ecofys
Status: Active

Rule 2:
Triggers:onDuringLogin
User:automatic
Access: Manager, Administrator,Registered, Author, Editor, Publisher, Super Users
Confition: cb_sharegroup / Does Contain / CATO2
Auto: Join Groups
Groups: CATO2
Status: Active

The problem is that when user2 logins in he is not added to the group(s). If I remove the condition, he is added.

The custom field cb_sharegroup has the following properties:
Type: Drop Down (Multiple select)
Display on profile as: Comma ","-separated line
Tab: Contact Info
Prefilled value at registration only:
Required: No
Show On profile: Yes: on line 1
Display field title in profile: Yes
Searchable in user list: No
User read only: yes
Show at registration: no
published: yes
size: 0

See also screenshots.

C:\fakepath\SS-2011-09-09_14.13.56.png



C:\fakepath\SS-2011-09-09_14.18.22.png

Nope. Still not working. I attached cb_sharegroup properties.