I bought my parents an iMac (I have a Mac Pro) and configured it at my house. Set us both up Google Talk accounts and had both computers Screen Sharing with iChat. Now from their house Screen Sharing won't work and no settings were changed. It will start Screen Sharing and disconnect in about 1 second (she saw my screen for about 2 seconds once and you can always see the account name in big letters warning that screen sharing is starting) no matter which one starts are which screen we share. I don't have a camera but voice sharing (we can be talking the whole time) and text messages work fine. Screen Sharing is enabled on both and I checked the speed of their internet connection and all is OK.
How can I test to see which system isn't working correctly or what other settings to check?
How can I test to see which system isn't working correctly or what other settings to check?