Runtime Error in Vista

Here goes the relevant parts of the DLL:

// Blitz3D ====================================================================
//-----------------------------------------------------------------------------
.lib "B3D_AppBase.dll"
app_DDHook%(pDD7%):"_app_DDHook@4"
app_DDUnHook():"_app_DDUnHook@0"
app_DDWasLost%():"_app_DDWasLost@0"


// C++ ========================================================================
//-----------------------------------------------------------------------------
#include <windows.h>
#define DIRECTDRAW_VERSION 0x0700
#include <ddraw.h>


//-----------------------------------------------------------------------------
#define BBDECL extern "C" _declspec(dllexport)
#define BBCALL _stdcall


//-----------------------------------------------------------------------------
static LPDIRECTDRAW7        _b3d_pdd;      // pointer to DirectDraw object
static LPDIRECTDRAWSURFACE7 _b3d_pddsPrim; // pointer to primary DirectDraw surface


//-----------------------------------------------------------------------------
BOOL APIENTRY DllMain( HANDLE /*hModule*/, DWORD ul_reason_for_call, LPVOID /*lpReserved*/ )
 {
 switch( ul_reason_for_call )
  {
  case DLL_PROCESS_ATTACH: break;
  case DLL_THREAD_ATTACH: break;
  case DLL_THREAD_DETACH: break;
  case DLL_PROCESS_DETACH: break;
  }
 return TRUE;
 }


//-----------------------------------------------------------------------------
// called by 'app_DDHook()'
HRESULT WINAPI _surfaceEnumCallback_GetPrimary( LPDIRECTDRAWSURFACE7 lpDDSurface, LPDDSURFACEDESC2 lpDDSurfaceDesc, LPVOID /*lpContext*/ )
 {
 if( lpDDSurfaceDesc->ddsCaps.dwCaps & DDSCAPS_PRIMARYSURFACE )
  {
  _b3d_pddsPrim = lpDDSurface;
  return DDENUMRET_CANCEL;
  }
 lpDDSurface->Release();
 return DDENUMRET_OK;
 }


//-----------------------------------------------------------------------------
// Should be called after B3D graphics mode has been set
BBDECL BOOL BBCALL app_DDHook( LPDIRECTDRAW7 pDD )
 {
 if( pDD )
  {
  _b3d_pdd = pDD;
  return (DD_OK == _b3d_pdd->EnumSurfaces( DDENUMSURFACES_DOESEXIST | DDENUMSURFACES_ALL, NULL, NULL, _surfaceEnumCallback_GetPrimary ));
  }
 return FALSE;
 }


//-----------------------------------------------------------------------------
// Should be called before B3D graphics mode is cleared
BBDECL void BBCALL app_DDUnHook()
 {
 if( _b3d_pddsPrim )
  {
  _b3d_pddsPrim->Release();
  _b3d_pddsPrim = NULL;
  _b3d_pdd = NULL;
  }
 }


//-----------------------------------------------------------------------------
// Should be called each time through Blitz3D main-loop
BBDECL BOOL BBCALL app_DDWasLost()
 {
 return (_b3d_pddsPrim && (DD_OK != _b3d_pddsPrim->IsLost()));
 }


// Usage ====================================================================
// On Start Up --------------------------------------------------------------
Graphics3D ...
SetBuffer BackBuffer()
If Not app_DDHook( SystemProperty( "DirectDraw7" ) ) Then /* Error */

// On Shut Down -------------------------------------------------------------
app_DDUnHook()
EndGraphics

// During Main Loop ---------------------------------------------------------
If app_DDWasLost() Then /* reset display, reload graphics */
UpdateWorld: RenderWorld: Flip 

I see that in my first post above, I stated that on losing the surfaces, I do a restoreAllSurfaces. Actually, I just do something like

app_DDUnHook()
EndGraphics
Graphics3D ...
SetBuffer BackBuffer()
app_DDHook( SystemProperty( "DirectDraw7" )
; Reload all graphics

It's a brute force way but I feel more at ease just tearing everything down, and building it all back up.

HTH,
David