Unresolved External Symbol - Only in Release mode

Question

I'm using Visual C++ 6, and my application builds and runs fine in debug mode, but I get these two Unresolved External Symbol errors when trying to build in Release mode:

OverUnderReportDoc.obj : error LNK2001: unresolved external symbol "public: virtual int     __thiscall COverUnderReportDoc::GenerateReport(void)" (? GenerateReport@COverUnderReportDoc@@UAEHXZ)

OverUnderReportDoc.obj : error LNK2001: unresolved external symbol "public: virtual bool __thiscall COverUnderReportDoc::DoReport(void)" (?DoReport@COverUnderReportDoc@@UAE_NXZ)

COverUnderReportDoc is a class derived from CReportDoc, which is derived from CDocument, part of the MFC framework.

Here are the function declarations:

public:

virtual int GenerateReport(void);
virtual bool DoReport(void);

And the definitions:

bool COverUnderReportDoc::DoReport(void)
{

// Instantiate the dialog
CCriteriaDlg dlg;
m_Report.BreakSpace(FALSE);

// Get a pointer to the window
CWnd* pWnd = AfxGetApp()->m_pMainWnd;

// When OK is clicked...
if (dlg.DoModal() == IDOK)
{       
    // Set the document title
    SetTitle("Inventory Over/Under");

    // Copy some values from the dialog to member variables

    GenerateReport();

    pWnd->ShowWindow(SW_MAXIMIZE);

}
else
{
            // If Cancel is clicked, close the program
    if(pWnd)
        pWnd->PostMessage(WM_CLOSE);
    return false;
}

return true;
}

int COverUnderReportDoc::GenerateReport(void)
{

// write the headers to the report
// if there was no problem
if (DoHeaders())
{
    // assemble the report data
    // if that went well
    if (ScanFile())
        // write the summary to the report
        DoSummary();
}
// return the document status
return m_nStatus;
}

I'm really not sure how to resolve this, those methods aren't in any libraries, and the class compiles fine, so I don't know why it doesn't see them while linking. Anyone have any ideas?

EDIT: Here are my project options:

Release Project Options:

(C/C++ tab of Project Settings)

/nologo /Zp1 /MD /W3 /GX /O2 /D "WIN32" /D "NDEBUG" /D "_WINDOWS" /D "_AFXDLL" /D   "_MBCS" /D "BTI_WIN_32" /FR"Release/" /Fo"Release/" /Fd"Release/" /FD /c 

(Link tab of Project Settings)

MYLIB.lib w3btrv7.lib VERSION.LIB /nologo /subsystem:windows /incremental:no /pdb:"Release/OverUnderReport.pdb" /machine:I386 /out:"Release/OverUnderReport.exe" 

Debug Project options:

(C/C++ tab of Project Settings)

/nologo /Zp1 /MDd /W3 /GX /ZI /Ot /D "WIN32" /D "_DEBUG" /D "_WINDOWS" /D "_AFXDLL" /D "_MBCS" /D "BTI_WIN_32" /FR"Debug/" /Fo"Debug/" /Fd"Debug/" /FD /GZ /c

(Link tab of Project Settings)

VERSION.LIB MYLIB.lib w3btrv7.lib /nologo /subsystem:windows /profile /debug /machine:I386 /out:"Debug/OverUnderReport.exe" 

Answer 1

Line #102 at pastebin.com/e1E0WcBT :

#ifdef _DEBUG

results in skipping all definitions of member functions from that point when built in release mode.