Serviio won't detect WIRED devices

Serviio won't detect my WIRED (TV, PS3) devices and vice-versa. Both TV and PS3 are hard wired to the home network and can access the internet just fine.

[Internet] --> [Huawei HG655B modem / router, DHCP enabled] --> [HP ProLiant Microserver + WHS 2011 running Serviio 1.1, wired, fixed IP 192.168.1.100]
--> [PS3, wired, fixed IP 192.168.1.101]
--> [Samsung TV UE40D5000, wired, fixed IP 192.168.1.102]
--> [Nexus 7 Tablet, wireless, dynamic IP provided by DHCP]
--> [Galaxy S3 + Galaxy S2, wireless, dynamic IP provided by DHCP]
--> [Windows 7 laptop, wireless, dynamic IP provided by DHCP]

WHS / Serviio:
- bound IP set to 192.168.1.100
- firewall disabled completely so no ports should be blocked, right?
- Serviio displays it's own IP (192.168.1.100) and IPs of all wireless devices when i start a rendering application on the wireless devices.
- PS3 / Samsung TV are not detected and vice-versa

Nexus 7 / Galaxy S3/S2 / Windows 7:
- all can see Serviio running on WHS 2011 and can stream from it no problem

Windows 7 laptop:
- if I install Serviio on Windows 7 laptop, both PS3 and TV are detected by Serviio and vice-versa!!!

PS3:
- if I switch to wireless connection on my PS3, PS3 detects Serviio and vice-versa!!!

=> So I know it is a networking (setup) problem / configuration issue on the WHS 2011 machine that is blocking the wired communication of Serviio to the PS3 / Samsung TV, I just need your help identifying what this is. Can anyone help?

Thank you very much!

Update, I tried the following without success:

- reset the router to factory defaults
- reset the TV to factory defaults
- tried different fixed IP's on the SAmsung TV, even tried with auto IP, still Serviio on WHS will not detect the TV / PS3 and vice-versa.

I have managed to play the content from the WHS maschine runing Serviio to the Samsung TV via AllShare the following way:

[WHS running Serviio] --> wired --> [rounter] --> wifi --> [Nexus 7 tablet running BubbleUPnP, renderer selected the Samsung TV and library selected the Serviio server] --> wifi --> [router] --> wired --> [Samsung TV] = great success
but
[WHS running Serviio] --> wired --> [router] --> wired --> [Samsung TV] is still not working... (