Domoticz

Newbie to Domoticz and after succesfully (and fast!) linking of my existing KaKu light switches and doorbell I am stuck. I want to link my Visonic K940MCW 868MHz motion sensors to Domoticz through the RFXcom433 with EXT2 v1025 firmware - but it doesn't work. Domoticz does not see the motion sensors, although the RFX mode is set to AC and Visonic. Of course I am unable to transmit but according to the compatibility matrix of the RFXcom433 there should be no problem in receiving. Searching this forum and using Google had not enlightened me. What am I doing wrong?

868 MHz devices can never be received bij RFXCom433.

I'm sorry, I forgot to type in the E - I have a RFXtrx433E which according to the manual should work in receiving Visonic - but then I'm afraid that it is only 433 MHz - bummer..

I guess I'll have to go this way then, which for now is a bit over my head.
Or is there another way to link these devices tot Domoticz?