Unable to use wireless internet after using Airplay on the device

I have my Time Capsule connected to a router provided by internet company. I use my Time Capsule for broadcasting the wireless network and also for wired ethernet connections for close by devices. I also have an AirPlay enabled Dennon Amplifier (connected by ethernet to Time Capsule) and a separate airport express in another room connected to the wireless network broadcasted from the Time Capsule.

Whenever i use Airplay from my iphone to play though either the Dennon or Aiport Express in the other room, then I am unable to access internet from the mobile phone or any other wireless device. The wired devices are still all ok. Once I restart my router provided by the internet company, then it is all fine again and i can use internet, until i use Airpay again, then internet doesnt work.

I have one wireless that is broadcast and everything connects onto that.

Is anyone else having the same problem and have managed to fix it? I have tried logging onto the router provbided by the internet company to see if there is any settings that be set up.. im thinking its a firewalling issue after the broacast of airplay on the network, but I cant find any settings relating to this on my internet company provided router.

Any help woruld be apprecated.

Thanks,l