Hi- I had my first skype video call last night with another mac user and was hoping to ask two questions... first, the audio had a terrible echo and a high pitched noise in the background. Is there a way to fix this? Also, the receiver was able to see me on his mac but I got no picture of him on my mine (although the little green light on my camera was on and my own picture was on the screen). Is there any way of telling which of our computers cameras aren't configured correctly. This is with a macbook so I have the camera built in. Thanks in advance!!