Arduino - Rako lighting interface

I am new to Arduino and software code and i am having some issues controlling my Rako lighting bridge:

1st attempt: HTTP posts with Arduino Uno + wifi Shield:
Works but too slow (2 seconds between each post).. I needed to control several channels at the same time.

2nd attempt with Telnet with Arduino UNO + wifi shield:
Could not make telnet work over the wifi shield

3rd attempt with Telnet with Arduino UNO Ethernet v3:
Worked great during 3 days then had to reset the Rako bridge (Arduino was still communicating with the bridge and the bridge was still responding, but the bridge was not controlling the lights through telnet anymore, although it could still be done with the iPhone app)

As the IPad and IPhone Rako App and demoPad app works with UDP, and as Telnet is normally reserved to the setup PC software, I decided to switch to UDP.

4th attempt: UDP with Arduino UNO Ethernet v3
I sniffed the UDP packets from the IPhone App and matched the protocol wih the page 3 of a doc on the net ( was unabled to send Hex packets from the Arduino.

Has anyone successfully controlled a Rako lighting system from an Arduino board ?