MainFrame Aborts When Created

I have an AppWizard-created MFC program that will not run on my development
computer any longer. This just happened. It *will* run on other computers.
Older versions of the same program which I know I debugged on my development
computer will now not run. All other dialog-based and MDI programs run
okay. This one just closes immediately and there are no error messages
other than the memory leaks that I would expect.

This is VC++ 6.0.
The problem happens in Debug or Release mode.

In Debug the program closes immediately after this line:
  CMainFrame* pFrame = new CMainFrame;

If I debug into the module AFXMEM.CPP I get this:

void* PASCAL
CObject::operator new(size_t nSize, LPCSTR lpszFileName, int nLine)
{
 return ::operator new(nSize, _CLIENT_BLOCK, lpszFileName, nLine);
}

nSize == 60836, lpszFileName is the path to MyApp.CPP and nLine is 126.
The return is 0x00ae0068.

Is there enough info here to deduce anything?

Doesn't it seem like something is corrupted on my development computer?

Thanks for help,
Tom S