Can CWinThread::SuspendThread suspend yourself?

I'm not sure if this is a generic coding bug (e.g. buffer overflow
somewhere), a violation of a Win32 constraint on SuspendThread, a violation
of an MFC constraint on CWinThread::SuspendThread, or a bug in Visual Studio
2005's version of MFC or in Windows XP or where.

CWinThread *T = AfxBeginThread(f, p);

UINT f(LPVOID p) {
  // do some stuff
  T->SuspendThread();
  // when someone resumes us, we continue
}

Running in debug mode under control of Visual Studio 2005, about 66% of the
time this runs silently, but about 33% of the time it gets an exception on
an assert in afxwin2.inl, which makes no sense to me. It seems that
m_hThread is non-NULL as it should be, and the assert complains that a
memory read failed at a highly suspicious memory address. The memory
address varies but is always a very small multiple of 4, looking very
suspiciously like a handle value not a memory address, making me wonder
who's trying to read memory there.

While typing this message I observed that __cdecl is missing from the
declaration of f. But Visual Studio 2005 didn't issue any error message
about the call to AfxBeginThread. I don't think I know the real problem
yet.