Scene triggers twice ???

I have a scene to send a IR command to my satellite receiver to turn it on/off (its a on/off toggle). I noticed that after about a minute the satellite receiver goes off again. I put a notification on the scene to see where that is coming from. In my Vera Alerts I can see the scene is triggered again with varying delays, between 30 secs and 10 mins, without me triggering it ! It does not matter if I trigger the scene manually by clicking (once !) on the scene in UI5, or if I trigger the scene with a PLEG action.
I am completely baffled by this.