If you use a proxy (transparent or not) all requests reach the web servers with the IP of the proxy. This can be a problem with some servers (probably iTunes is one of them) because if two users of your LAN make requests in the same time slot the server thinks it is a duplicate. For this reason Zeroshell has two type of capturing rules:
– “Capture” with which it is possible to define interfaces, clients and servers to be redirected to the proxy;
– “Do not capure” with which you can exclude the redirection and the http requests are directly forwarded.
You should just exclude the IP subnets of iTunes.