Wifi disconnecting when left idle

[Beanz]

Hi all,

I have recently changed my router to an ASUS RT-N56U and have been having problems where i need to reboot the Pi to get the network connected after its been left for a while, once booted i can access my NAS and thingsa tend to stream ok.
Is there a setting within Xbian that keeps communications open or is there something standard in router settings that would keep the connection alive that i can look for ?

I am running a wifi bridge to connect wirelessly using the ethernet connection as the Edimax USB dongle i recently bought is giving me problems where i don't get a network connection and when checking System Settings lots of things including - OS, MAC Address, Connection etc - show as BUSY, but that a different issue

Thanks for any pointers.