Streaming from Mac to WDLiveTV

Sorry if this is a duplicate post, but I’ve had a good old dig around and cant find anything specifically to do with my particular problem.

I have my mac with a 2tb GoFlex NAS drive connected to it (plugged into the same router as my mac) which my WDLiveTV box picks up and plays no problem.

I also have a WD 1tb external hard drive also plugged into my Mac and I’ve selected it in the system preferences–>sharing section, but I can’t get my WDLiveTV to pick it up.

What am I doing wrong ?

Thanks in advance

Review the steps on the link below to share files from the Mac.

Or, if you’re using OS X 10.7 or later, use this method: