Problem with wireless SMC router

I purchased a NP5670 from powernotebooks.com with the wireless router
and card option and for some reason the router resets itself
periodically while I have the wireless card in the laptop. If I leave
the laptop alone it works fine. It even works fine when I'm just
browsing the net. But if I try to listen to internet radio or watch
internet tv or even download a file (like over 3 megs) it gets partway
thru, hangs, then resets. Could this just be a configuration issue and
I'm just not getting it set up right?

The router is a SMC Barricade Turbo 2404WBR, and the card I'm using
is... well, I'm not sure exactly, but it's the card powernotebooks
sent me with the router. I'm fairly sure they're not the same brand,
though.
Any help with this would be vastly appreciated. Thanks!