Can't do a video chat in 10.4.7

Question

I have a G5 (1.8 - 2 gigs of RAM) that was working perfectly with a video chat and then updated to 10.4.7 and it will no longer do a video chat with a Powerbook that has 10.4.6 or my iMac G5 at home that also has 10.4.6. Both of these machines in different states have plenty of bandwidth so that isn't the issue.
The video WILL work with a Powerbook on the local network with a kbps rate of 700+, but what is up with that?
Anyone else experience the same thing? I HAVE to have my machine back up and functioning with my iSight tomorrow. I have never used Pacifist before, but I'll check the threads for installing it to try and get a previous version of iSight, but I'm not sure how to do that if it's only available as Software Update.
HELP!
A lab full of G5's   Mac OS X (10.4.6)  

Answer 1

I thought I would add some more info. In looking at the log that is sent to Apple it says that it's a 'SIPConnectIPPort failed':
Date/Time: 2006-06-27 18:22:12.331 -0500
OS Version: 10.4.7 (Build 8J135)
Report Version: 4
iChat Connection Log:
AVChat started with ID 2080454773.
(my screenname): State change from AVChatNoState to AVChatStateWaiting.
0x7053fc0: State change from AVChatNoState to AVChatStateInvited.
0x7053fc0: State change from AVChatStateInvited to AVChatStateConnecting.
(my screenname): State change from AVChatStateWaiting to AVChatStateConnecting.
(my screenname): State change from AVChatStateConnecting to AVChatStateEnded.
Chat ended with error -8
0x7053fc0: State change from AVChatStateConnecting to AVChatStateEnded.
Chat ended with error -8
Video Conference Error Report:
4.003926 @:0 type=4 (00000000/2)
[VCSIP_INVITEERROR]
[19]
4.003589 @SIP/SIP.c:2437 type=4 (900A0015/2)
[SIPConnectIPPort failed]
2.002912 @SIP/SIP.c:2437 type=4 (900A0015/2)
[SIPConnectIPPort failed]
Then it has a TON of other stuff. I'm assuming it's a Quicktime issue, but who knows.
Again, anyone else who has updated to 10.4.7 connected on a video chat successfully?
A lab full of G5's   Mac OS X (10.4.6)