loosing messages leakes my app...

hello everyone...

i have a htread-aware ctrl-class that posts commands from other
threads automatically to the gui-thread before executing them. looks
like this:

//-----------------------------------------------------------------------------
// prepares a message
bool CQControl::_GUIPost(QUAD qMsg, PCVOID pMsg, DWORD dwLen) const {
    SQMsgBlock* pMB = NULL;
    try {
        pMB = new SQMsgBlock;
        pMB->dwLen = dwLen;
        if (dwLen == NULL)
            pMB->ptBlock = NULL;
        else {
            pMB->ptBlock = malloc(dwLen);
            memcpy(pMB->ptBlock, pMsg, dwLen);
        }
        pMB->qType = qMsg;
        pMB->hReturn = 0;
        if (_GUIPost(pMB))
            return true;
        _GUIPostDelete(pMB);
        return false;
    } catch (...) {
        _GUIPostDelete(pMB);
        return false;
    }
}

//-----------------------------------------------------------------------------
// post a message to the GUI-thread or execute it if called from GUI-
thread
bool CQControl::_GUIPost(SQMsgBlock* pMB) const {
    if (AfxGetThread() == _GUI()) {
        // we are the GUI-thread, so we call receicve-fn directly...
        const_cast<CQControl&>(*this)._GUIReceived(pMB);
        return false; // delete block
    }
    if (_HWND() == 0)
        return false;
    pMB->hControl = _HWND();
    return (::PostMessage(_HWND(), WM_QWCOMMAND, 0, (LPARAM) pMB) != 0);
}

//-----------------------------------------------------------------------------
// delete and free a Msg-Block
void CQControl::_GUIPostDelete(SQMsgBlock* pMB) {
    if (pMB == NULL)
        return;
    free(pMB->ptBlock);
    delete pMB;
}

//-----------------------------------------------------------------------------
// returns true if GUIPost received
bool CQControl::QPreTranslateMessage(MSG* pMsg) {
    if (pMsg == NULL)
        return false;
    if (pMsg->message != WM_QWCOMMAND)
        return false;
    SQMsgBlock* pMB = reinterpret_cast<SQMsgBlock*>(pMsg->lParam);
    _GUIReceived(pMB);
    _GUIPostDelete(pMB);
    return true;
}

in the CWnd, the fn PreTranslateMessage() calls QPreTranslateMessage()
to catch my commands; all runns fine exept that i still have some
leaks, so even if ::PostMessage() returns that the message was posted,
it never gets to the PreTranslateMessage() of the ctrl.

So the question is: is there an application-wide PreTranslateMessage()
for the GUI-Thread that i can override to dispatch certain messages
myself?