Error when on dynamically inserted nodes in OMNeT++

Question

I'm trying to make an scenario in OMNeT with different Areas. Each area is a compound module which have many nodes inside, such like a city or something like that. I want that nodes moves from one area to another. I already done that, but the nodes that are dynamically inserted in their new areas throws error when they are going to perform a transmission. The error is not throwed in all transmissions, just sometimes. I debugged my code and the error is in Signal.cc file, seems that node doesn't find the radioMediumModule. I'm using IEE802.15.4 communications and SensorNode module. I think thay maybe is an allocation of memory problem, since the error does not always throw. Thanks in advance.