I added a helpAbout menu item to my mfc app. I decided to make the ddlg derive from CDHTMLDialog.

I override the OnInitDialog() method in my derived class and the first thing I do is call the parent's OnInitDialog() method.

I then put in code that sets the title.

On some machines this works fine, but on others it crashes in the call to

CDHtmlDialog::OnInitDialog() - Trying to read a null pointer.

the call stack has nothing useful - it is in mfc90.dll

Is this a potential problem with mismatches of mfc/win32 dlls?

It works on my vista machines but crashes on a win2003 server box.

BOOL HTMLAboutDlg::OnInitDialog()
{
   // CRASHES on the following line
    CDHtmlDialog::OnInitDialog();
    CString title = "my title";  // example of setting title

            // i try to get version info
        //set the title
        CModuleVersion ver;
        char   filename[ _MAX_PATH ];
        GetModuleFileName( AfxGetApp()->m_hInstance, filename, _MAX_PATH );

        ver.GetFileVersionInfo(filename);
        // get version from VS_FIXEDFILEINFO struct
        CString s;
        s.Format("Version: %d.%d.%d.%d\n",
                HIWORD(ver.dwFileVersionMS), LOWORD(ver.dwFileVersionMS),
                HIWORD(ver.dwFileVersionLS), LOWORD(ver.dwFileVersionLS));

        CString version =   ver.GetValue(_T("ProductVersion"));
        version.Remove(' ');
        version.Replace(",", ".");
        title = "MyApp  -  Version " + version;

    SetWindowText(title);
    return TRUE;  // return TRUE  unless you set the focus to a control

}

And here is the relevant header file:

class HTMLAboutDlg : public CDHtmlDialog
{
    DECLARE_DYNCREATE(HTMLAboutDlg)

public:
    HTMLAboutDlg(CWnd* pParent = NULL);   // standard constructor
    virtual ~HTMLAboutDlg();
// Overrides
    HRESULT OnButtonOK(IHTMLElement *pElement);
    HRESULT OnButtonCancel(IHTMLElement *pElement);

// Dialog Data
    enum { IDD = IDD_DIALOG_ABOUT, IDH = IDR_HTML_HTMLABOUTDLG };

protected:
    virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
    virtual BOOL OnInitDialog();

    DECLARE_MESSAGE_MAP()
    DECLARE_DHTML_EVENT_MAP()
};

I can't figure out what is going on - why it works on some machins and crashes on others.

Both have VS2008 installed

EDIT:

VS versions

VISTA - no crashes 9.0.30729.1 SP

2003 server: (crashes) 9.0.21022.8 RTM