PS3 unable to detect "wired" UPNP setting

I have a Linksys WRT54GX4 firmware 1.00.20. I recently setup a new HP470 w/MS Windows Home Server to store my downloaded T.V. shows (Divx / Xvid format). I'm trying to stream the videos to my PlayStation 3 in another room. Here is the snag, I have been successful in doing this if I setup my Playstation 3 to use wireless connection to my WHS, but the playback suffers from "stuttering". If I use the "wire" method, I occasionaly see my WHS pop up, but am unable to playpack any videos. The only diference between "wired" & "wireless" is UPNP is detected by the "wireless" option of the PS3.
It doesn't seem Linksys (Cisco) is supporting this model anymore by the lack of any recent firmware upgrade. Any thoughts on this?