Connecting a PC a stereo - wirelessly

Hi guys and gals - wondered if someone might be able to shed a little light on a headscratcher of mine.

I'm trying to get my PC to connect to my new stereo that my lovely wife bought for me recently.

We currently have a wireless network set up - a laptop connects without problems. However, I am trying to connect my Sony NAS-50HDE stereo to my PC via the recommended Buffalo WLI-U2-KG54AI-3 - USB WiFi Adapter.

I am using a Linksys WAG354G router but cannot seem to get it to even "see" a signal from the stereo.

The instructions suggest a simple "plug and play" setup, but I've tried for two nights now and seem no nearer a solution.

Any advice you could give would be most appreciated!

Wayne