C++: Error deleting array of pointers

I am having some problems when the destructors of my program are called. I have these clases:

• myModule is the base class where the array of pointers is.
• myModule_in is a subclass that represents a module with input ports (there is a myModule_out and a myModule_inout that will not be showed here, since it is not necessary).
• moduleC is one of the input ports modules (moduleA and moduleB are myModule_out and myModule_inout).

myModule:

    class myModule
    {
    public:

      myPort* secondary_ins[NUM];

      myModule() {}

      virtual ~myModule()
      {
        for(int i=0; i<NUM; i++)
        {
          if(secondary_ins[i])
            delete secondary_ins[i];
        }
      }

      virtual void connect(myModule &m) = 0;
    };

myModule_in:

    class myModule_in : public myModule
    {
    public:
      virtual ~myModule_in() {}

      virtual void connect(myModule &m)
      {
        secondary_ins[ins] = new myPort();
        ...
      }

    };

moduleC:

    class moduleC : public myModule_in
    {
    public:

      moduleC();
      ~moduleC() {}

      void connect_modules() {...}

    };

main:

    int main(...)
    {
      moduleA mA;
      moduleB mB;
      moduleC mC;
      ...
      mA.connect(mB);
      mB.connect(mC);
      ...
      return 0;
    }

This code compiles correctly and works fine, until the end of execution, where I get a segmentation fault at: delete secondary_ins[i]; being called from return 0;. The strange thing is that the other modules' destructor are also called and do not have any problem. Maybe there is something wrong with the handling of array of pointers inherited from a base class or something? Any ideas?

Thanks :)