Can't stream via Airplay to B&W Zeppelin

Hi.

A mate has just bought a B&W zeppelin so he can use as a dock and also to stream to.

We've got it all set up on his network and are using Win7 on a 'new' laptop. ITunes is latest version.

All set up instructions have been followed and the B&W seems to be set up correctly on the network. Win7 on the laptop is 'seeing it' on the network tree.

The issue we have is that ITunes isn't presenting the airplay icon which I understand will instigate the streaming to the zeppelin.

I suspect it's a network issue but before I get into the minefield that presents, I wondered if anyone has any potential simple fixes???

He uses an NTL modem/router but I'm not sure of the type at present.

Cheers for any help.

Regards Paul