Whs2003 & Panasonic Gt50 Streaming Files

I have recently purchased the Panasonic Viera TX-P50GT50B after owning a sony bravia. 

I used to run PS3 media server on my WHS and the sony could play the files fine but for some reason the Panasonic can't even find any files but it can see the server.

Has anybody else managed to get the panasonic to see WHS2003 and if so what programme are you using?

Thanks in advance.