When using AppleTV device going thru the proxy, you might get an error message on the tv saying "error occured, please try again".
Please install the below policy in the local policy file.
Management Console->Configuration->Policy->Policy Files->Local Policy->Text editor->Install
Append the following and install policy
<Proxy>
request.header.user-agent=AppleWebKit bypass_cache(yes)
<Proxy>
request.header.user-agent=AppleCoreMedia bypass_cache(yes)
<Cache>
request.header.user-agent=AppleWebKit cache(no)
<Cache>
request.header.user-agent=AppleCoreMedia cache(no)