I use TS-101 as mediaserver (Twonky) with Dlink DSM-520.

It works good for me.
I use it to play local movies, clips, music
like several hours every day...

OK.
In fact,Twonky does not show some files
due to unknown codec or container.
Also DSM-520 does not play some files for the same reason.
But most files work fine.
(Other files can be reconverted to supported format).

Also I've tried to get ShoutCast streaming radio played.
And it worked too (I don't use it)

So the problem may be in your file formats, access rights or
network (like router capability of streaming media routing, firewall
rules, uPnP support etc.)

- DI-624 Wireless Router (rev. D f/w: 4.04 beta40)
- DSM-520 Media Player(f/w: 1.04.05wwp (not US-EN))
- TS-101 Media Server (f/w: 2.1.1 with telnet support)
(also used as SMB fileserver, web-server, ftp etc.)

DSM-520 works WIRED (not WiFi-ed) to router.