I have been utilizing GoToMeeting pretty often these days. I had one major issue where I was unable to show my slideshows in presentation mode while using GoToMeeting and Apple Keynote. Whenever I flipped on presentation mode, the person on the other side would see black.
After some trouble shooting with the GoToMeeting support team, they said they know of a work around. So to save you all time, here is what you need to do.
(1) Open Keynote
(2) Go to the “Preferences” section
(3) Click on “Slideshow” tab
(4) Check off “Allow Exposé, Dashboard and others to use screen”
Then GoToMeeting should show your presentation in presentation mode. Do keep in mind that the GoToMeeting presentation tool where people can ask questions, does not display to the presenter in presentation mode.
Hopefully this will help others with the same question.