ichat webcam stops working

For nearly a month I've had this problem. My ichat suddenly stopped working, when it came to video calls. I would get this timing out message: "There was a communication error during your chat." I've tried multiple connection, Apple's version of "safe mode", spoke with a tech and even reset the SMC. I always get "There was a communication error during your chat" I looked at the log and couldn't narrow it down. I've hit "send to apple" and haven't had any response. I was told to try and apple store (Which I didn't do because I've tried various connections including one's that have worked in the past) or reformat. Today I fount the problem "internet sharing" it creates a conflict. When it's on ichat's video times out. So if you get "There was a communication error during your chat" check "internet sharing" under settings>sharing