iChat with multiple buddies

[Jim Soriano]

I've got this problem using iChat (10.2.4)...I can successfully start 
iChatting with 1st buddy.  When I go to add a 2nd buddy to the 
in-process chat by the following procedure:

"Choose 'Show Chat Participants' from the 'View' menu.  Click the 'Add 
(+)' button in the participants list and select people from the Buddy 
List to invite to the chat.  If you want to invite someone who is not 
in your Buddy List, select Other.  Enter the screen name of the person 
to invite."

The 'Add (+)' button remains dimmed and non-selectable even though I 
can see the 2nd buddy is online in my main buddy list and I can select 
them.  I can start a second separate chat with 2nd buddy, but that's 
not what I want...I want a conference!

(Both 1st and 2nd buddies are on various and sundry Windows machines 
running AOL IM client...probably Netscape.)

Any ideas?

Regards,

Jim