Reiving an unexpected command during the startup of the sensor

[TheoL]

I use the dimmer example as a basis for a new floor lamp. But for some kind of reason, the first command I receive is of the message.type 4. Which I'm not expecting (it's a dimmable lamp). My question is, who is sending the initial command? Is this done by the gateway or by the Home Automation controller?

I've just updated to MySensors 1.5.4 (comming from 1.5) but it gives the same result?