Confused about system requirements for video with iChat

[wwooden]

Ok, so my dad, my sister, and my girl friend and I all have tiger installed on our computer. The computers go as the following:
Dad : Dual 1.8 G5
Sister : 667 G4 Titanium
Girlfriend : 1.67 G4 15" PB
Mine : 1Ghz 12" PB

My dad tried to start a multi video conference with my girlfriend and I and it wouldn't let us do it. According to the Apple website, you need a dual 1Ghz G4 or a G5 computer to start a multi video chat, but it just wasn't working for us, apple iChat site. So then we went to the iChat help and it told us what is in the picture, that you need a Dual 1Ghz G4 or a Dual 2 Ghz G5 to start a video conference. I thought this was crazy that a G4 could do it but my dads dual 1.8 G5 couldn't. That completely messes up our plan to do video chats with my sister in Paris, France. So which one is correct? I am really pissed off at Apple if the second is true.

 

[wwooden]

I was doing some searching around the Apple support and found this picture

It says that you only need a dual 1Ghz G4 to start an 80 * 60 resolution video and so on. It still doesn't solve the problem as to why it didn't work for us. Is there a way to set the resolution of the video conference before it starts? We have the bandwidth set none so that shouldn't be a problem.