G+ hangouts

You can join an existing one that appears in your stream, ie one soneone else started. But you cant create a new ine from the google+ android app.
 
I joined in a hangout on my Wifi only Xoom. I could see and hear them but they could only see me. The little microphone on the bottom of my screen had a line through it. I assume this is why they could not hear me. Anyone else have this problem or know how to change it.