VC++ .net 2003 compile problem

[fudicator]

Hello, i've got a really anoying bug that i cant seem to figure out.. The code comes from a 2005 project which needs to be compiled in a 2003 project. The code is as follows:

// CitectAPIManagedDll.h

#pragma once

using namespace System;
using namespace System::Runtime::InteropServices;

namespace CitectAPIManagedDll
{
   /// Create a unmanaged wrapper structure as the placeholder for unmanaged class
   /// members as exported by the DLL. This structure/class is not intended to be
   /// instantiated by .NET applications directly.
   public __gc struct CitectAPIUnman
   {
      /// Define the virtual table for the wrapper
      typedef __gc struct __VTB
      {
         void (*Open)(CitectAPIUnman*, System::String*, System::String*, System::String*, System::Int32*);   
      };

   public:
      char* id;
      static __VTB *vtb;   

      /// Perform all required imports. Use "ThisCall" calling convention to import
      /// functions as class methods of this object (not "StdCall"). Note that we
      /// pass this pointer to the imports. Use the "decorated name" instead of
      /// retreived from the DLL as the entry point.
      [DllImport("CTAPI.dll",
              EntryPoint="ctOpen",
              CallingConvention=CallingConvention::ThisCall)]
      static void Open(CitectAPIUnman*, System::String*, System::String*, System::String*, System::Int32*);
      
      /// Delegates of imported virtual methods for the virtual table.
      /// This basically is hacking the limitation of function pointer (FP),
      /// as FP requires function address at compile time.
      static void VOpen(CitectAPIUnman* w, System::String* computer, System::String* username, System::String* password, System::Int32* mode)
      {
         Open(w, computer, username, password, mode);
      }
   };

   /// Managed wrapper class which will actually be used by .NET applications.
   public __gc class CitectAPIWrap
   {
   public:
      /// User-defined managed wrapper constructor. It will perform a few tasks:
      /// 1) Allocating memory for the unmanaged data
      /// 2) Assign the v-table
      /// 3) Marshall the parameters to and call the imported unmanaged class constructor
      CitectAPIWrap()
      {
         tv = new CitectAPIUnman();
         CitectAPIUnman::vtb->Open = CitectAPIUnman::VOpen;
      }   

      /// Let the v-table handle method overriding
      virtual void Open(System::String* computer, System::String* username, System::String* password, System::Int32* mode)
      {
         CitectAPIUnman::vtb->Open(tv, computer, username, password, mode);
      }

   private:
      CitectAPIUnman *tv;
   };
}

i get the following compile error in my header file:
error C2440: '=' : cannot convert from 'void (__clrcall CitectAPIManagedDll::CitectAPIUnman::* )(CitectAPIManagedDll::CitectAPIUnman __gc *,System::String __gc *,System::String __gc *,System::String __gc *,int __gc *)' to 'void (__clrcall *)(CitectAPIManagedDll::CitectAPIUnman __gc *,System::String __gc *,System::String __gc *,System::String __gc *,int __gc *)'

my cpp file is as follows:

// This is the main DLL file.

#include "stdafx.h"

#include "CitectAPIManagedDll.h"

using namespace CitectAPIManagedDll;

/// Unmanaged wrapper static data initialization
CitectAPIUnman::__VTB *CitectAPIUnman::vtb = new CitectAPIUnman::__VTB;

i get the following compile error in my cpp file:
.\CitectAPIManagedDll.cpp(10) : error C2374: 'vtb' : redefinition; multiple initialization
        c:\pas\source code\database\citectapimanaged_2003\citectapimanageddll\CitectAPIManagedDll.h(23) : see declaration of 'vtb'
.\CitectAPIManagedDll.cpp(10) : error C3366: 'CitectAPIManagedDll::CitectAPIUnman::vtb' : static data members of managed types must be defined within the class definition


any ideas? this is the first time ive used 2003 to compile this project. your help is greatly appreciated.

thanks.