Thats similar to whats going on with me except with TV or itunes store movies
every 9 min it gets cut off to a black screen and yello triangel with itunes not available please try again later message, I can resume but 9 min later same thing, I think it has to to with Apple and maybe even their server
I called and spent most of the morning with them and we tried other things like netflix and streaming from my library and no problems at all.
I would play some music from your library and if it plays without cutting off then its itunes.
the tech support thinks it could be the servers we are using for itunes, or a bug issue with the new update but check if you can stream music fine through your library,
They suggested that everyone files a complaint throught the express lane to itunes store and this way we can see a fix faster