Problems with Airstation G54 and WRT54G

I have had this setup for a few months without any issues:

ADSL - Airstation G54 --- (wireless) --- WRT54G - ( wired) - Main PC,
Xbox360, Wii

Plus a laptop using the Airstation wirelessly as well.

Recently through, I'm finding that every so often the wireless stops
working for internet and local area networking. when i try to repair
the connection on the PC, it says "unable to refresh IP address". I
find that turning both routers off for 10mins can often do the trick.
Whilst the wireless isn't working, I've tried a wired connection to
the Airstation and that works fine.

Does anyone know what's going wrong here as resetting my routers every
so often is getting really annoying!

Thanks,

Chris