nick, i would start by updating your RFXCOM. DJSmiley is running v236 firmware on the RFXCOM, you are running v83....

Yes that was what i was thinking, yesterday i was running version 71 so i've updated to the latest version, number 83. Thats the latest version for my RFXtrx433 right? I can see ...

DJSmiley, did you have done something special to make the sensor work? I've bought the same sensor and i can't see it in Domoticz. I have the same protocols enable as you
http://s3.postimg.org/m4hgw3xhr/naamloos.jpg

The current version of my RFx
RFXCOM - RFXtrx433 USB 433.92MHz Transceiver ...