I think comodo is now blocking webcam connections where last version did not. What is the best way of allowing a particular site to male such connections?
Have a look in the logs and see what is being blocked. This will give you the definition of the rule you have to create to allow the access.
Ewen 
I am having the same prob. I have went into allowed applications on version 3. Along with defense + and added trusted applications and i still cannot broadcast audio or video over the net. When i disable the firewall it all works. i dont know how else to get it workin. please if you have an answer for me email me vampyre30@hotmail.com.
If you have a look in the logs, there will be some indication of why the transmission of the data was blocked. This will form the basis of any network rule that needs tobe created to allow the traffic.
Check your logs and post an extract of any relevant info back here.
Cheers,
Ewen