Help me, What's different? (empty interface inheritance)

i want to use class member function pointer.
i did as below case. but this program terminates with runtime error.

interface ICtlBase
{
   virtual ~ICtlBase(){};
   virtual void SetName(CString strData) = 0;
   virtual void SetID(CString strData) = 0;
};

class CCtlBase : public ICtlBase
{
public:
   virtual ~CCtlBase();
   virtual void SetName(CString strData);
   virtual void SetID(CString strData);

   typedef void (CCtlBase::*SetFunction)(CString);

   void ExeFunc(SetFunction);
};

void CCtlBase::ExeFunc(SetFunction func)
{
   SetFunction setFunction = func;
   this->*setFunction("aaaa");
}

class CCtlEdit : public CEdit, public CCtlBase
{
public:
   virtual ~CCtlEdit();
   virtual void SetText(CString strText);

   void Test();
};

void CCtlEdit ::Test()
{
   ExeFunc(SetText);
}

when this program run CCtlEdit::Test, this program terminate with runtime
error.

but i modified this program as below.

interface IBase   // empty interface
{
};

interface ICtlBase : public IBase
{
   virtual ~ICtlBase(){};
   virtual void SetName(CString strData) = 0;
   virtual void SetID(CString strData) = 0;
};

To my surprise, modified program work well.
only ICtlBase inherits empty interface IBase.

What happened? 

please Let me know this  situation.