HI,
To be clear.
The Snow Leopard computer is logging in to Google in a Web Browser ( Port 443)
The Messages beta computer is using SSL on port 5223 (as would Google normally)
I do have a Boot of OS X 10.7.4 that has iChat rather then Messages if you wish. ( don't really expect a lot of change between Off Line and On Line via a Browser Buddies that I have already tested.
The Option iChat 5 and iChat 6 to Start a Chat and the type from the File Menu may have a bearing (Messages opens a Text Chat called New Message with no Name (Contact) or Buddy (Screen Name) listed)
There is then a Video iCon to launch FaceTime for Contacts (iMessages people) or will do Video Chats iChat style for Buddies (As well as the Buddies menu that has not changed)
Psi is a a Java written app that is a Jabber Client.
I have it set to login to the Jabber.me.uk server, the Google Talk server and another Jabber server for testing
It does not have a Video Plug-in so I know that the "Buddy" (One of My Logins) does not have a Camera.
(the same applies to the Web Browser Plug-in for Google Talk on Intel computers the Plug-in is the same for Lion, Snow Leopard and Leopard if you have an Intel running Leopard)
I actually run GoogleTalk in my Messages boot on port 443
However this is only the Login port and iChat and Messages will use a different set for Video chats:-
Invites are on port 5678
SIP Invite (The bit behind the scenes) is then on port 16402 as first choice.
The actual Chat would also be on port 16402 no matter which typoe of Buddy it is (AIM, Jabber or Bonjour)
What I was trying to get across by listing the different apps and Computers is that I can create a scenario very close to the one you have and I do get somewhat similar results for a my Off Line Buddy section.
I will say that in iChat 5 Using the File Menu > New Chat > Video does not stay as soon as I put in a Jabber Buddy that cannot Video (It changes to Text)
I will try iChat 6 in Lion as soon as I can.
9:36 PM Wednesday; May 23, 2012
Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"
iMac 2.5Ghz 5i 2011 (Lion 10.7.4)
G4/1GhzDual MDD (Leopard 10.5.8)
MacBookPro 2Gb (Snow Leopard 10.6.8)
Mac OS X (10.7.4),
"Limit the Logs to the Bits above Binary Images." No, Seriously