Last night I installed Twonky on my PC, still no luck.
Read your post, and decided to try it (get nervous when fooling around with router settings).
Set the router to enable UPnP, and..............
Voila! It works! Finally! Yaaaaaaaaaaaaaay!
Still some issues. While the 3800 now shows up in Windows Media Player on my wife's PC, it still doesn't show up on mine.
On the 3800, Twonky shows up, but Media Player doesn't.
Next problem is the sound when playing files stored on my PC.
I ripped them with Media Player, saved them as .wav.
They play/sound fine on my PC.
In a word, awful. Lots of machine-gun type stuttering is the closest I can describe. Almost as if the connection isn't right, and cutting in and out VERY rapidly.
As I've posted, I have the 3800 connected to the router using Logitech's Play Link which uses RF for the two boxes to connect.
Could it be that the Play Link's RF is the culprit?
RF just isn't capable of "streaming" these files?
It works fine with net radio.
ETA: Re-ripped my files as .wma, and all is fine so far. The 3800 now shows up in Media Player. I also removed Twonky.