ichat & iSight help please!!

I have a G5 iMac (i'm a new mac user so please excuse my amateur jargon) and recently was given an iSight but I can't get it to work.
When i select to have a video chat with someone on my buddies list - a box pops up saying it's connecting to the other user but when they click on accept it comes back to me saying that it failed to start because I didn't respond.
I have checked the preferences and it says the firewall is off and i don't know what else to try.

Can anyone help?

Thanks in advance Lizzybear75

it might be something on their end that kills the connection have you tried to do it with more than one person?

1. are you using ichat or some other program?
2. what is the os on the other end?

another thing to consider is the other persons internet connection. both parties need to be on some form of high speed connection.

Yes - using iChat.
Both ends are G5 iMacs - so OS X but I don't know what version.

Both parties are on broadband