COM Method Release: Application Crashing

I think you dont understand the COM concept.
A simple implementation of a COM object:

class iUnknownImpl : public IUnknown
{
public: // IUnknown
  virtual HRESULT __stdcall  QueryInterface(REFIID riid,void** ppv)
    { return IID_IUnknown==riid?(*(IUnknown**)ppv=this,AddRef(),S_OK):E_NOINTERFACE; }
  virtual unsigned long __stdcall  AddRef()
    { return InterlockedIncrement(&_ref); }
  virtual unsigned long __stdcall  Release()
    { if(InterlockedDecrement(&_ref)) return _ref; delete this; return 0; }
  iUnknownImpl(){ _ref=1; }
protected:
  virtual ~iUnknownImpl(){ ASSERT(0==_ref); }
private:
  long  _ref;
};

You see if you want to hold an interface pointer - you have to call AddRef(). Other threads can meanwhile release the interface. If you dont need the interface anymore you must call Release() (once). If you want to cast an interface to another you have to call QueryInterface(). Remember: every call of AddRef() and QueryInterface() needs one Release.
After Release your pointer is invalid the object can be destroyed.
More AddRef's than Release's generate memory leaks. More Release's than AddRef's makes your app crash.
Regards.