Pane & CXTFlatTabCtrl

What is the simples way to put a CXTFlatTabCtrl with some Controls to a Pane.
Now i've a CWnd Containerand with this functions

class CTabbedPane : public CWnd
{
    CXTFlatTabCtrl  *m_pFlatTabCtrl;
    ....
};

// CTabbedPane message handlers
int CTabbedPane::OnCreate(LPCREATESTRUCT lpCreateStruct)
    {
    if (__super::OnCreate(lpCreateStruct) == -1)
        return -1;

    m_pFlatTabCtrl = new CExFlatTabCtrl;
    m_pFlatTabCtrl->SetFocusOnSetCurSel();
    m_dwTabStyle = FTS_XT_BOTTOM | FTS_XT_HASARROWS | FTS_XT_HSCROLL | FTS_XT_TOOLTIPS;
    // Create  the flat tab control.
    GetClientRect(m_rcTabs);
    if (!m_pFlatTabCtrl->Create(WS_CHILD|WS_VISIBLE|m_dwTabStyle , m_rcTabs, this, IDC_TABCONTROL))
        {
        TRACE0( "Failed to create flattab control\n" );
        return -1;
        }

    OnCreateChilds();

    // Set the active view to the second tab.
    m_pFlatTabCtrl->SetCurSel(0);

    m_pFlatTabCtrl->SetWindowPos(&wndTop, 0, 0, 0, 0,
        SWP_NOMOVE | SWP_NOSIZE | SWP_NOACTIVATE | SWP_FRAMECHANGED);

    SetRedraw(TRUE);

    RedrawWindow(0,0, RDW_INVALIDATE | RDW_UPDATENOW | RDW_ERASE | RDW_ALLCHILDREN);

    OnCreateComplete();

    return 0;
    }

void CTabbedPane::AddItem(DWORD dwId, LPCTSTR lpText, CWnd *pWnd)
    {
    m_pFlatTabCtrl->InsertItem(dwId, lpText, pWnd);
    pWnd->SetWindowText(lpText);
    m_WndList.push_back(pWnd);
    }

void CTabbedPane::OnSize(UINT nType, int cx, int cy)
    {
    __super::OnSize(nType, cx, cy);
    if (m_pFlatTabCtrl && ::IsWindow(m_pFlatTabCtrl->m_hWnd))
        {
        m_pFlatTabCtrl->SetWindowPos(NULL, 0,0,cx,cy, SWP_FRAMECHANGED);
        }
    }

void CTabbedPane::OnSetFocus(CWnd* pOldWnd)
    {
    int iIndex = m_pFlatTabCtrl->GetCurSel();
    if (iIndex >= 0)
        {
        CWnd *pWnd = m_pFlatTabCtrl->GetItemWindow(iIndex);
        if (pWnd)
            pWnd->SetFocus();
        }
    }

Now i've one problem with this.
i create this window with Size CRect(0,0,10,10), because i  don't know the Pane size.
I've 2 CTabbedPane Control in 2 panes.
Pane 1 is visible, Pane 2 is not visible.
Now i select a Tab from Pane2.
GetPane2().GetFlatTabCtrl().SetCurSel( 3 );
If i make now Pane 2 visible. Tab Button's& Tabs are not visible, because
some internal varibales, m_xGripperPos, m_nOffset have a negative value (-300).
Now i Create my window with CRect(0,0,600,100) and it work, but
i think this is a bug. OnShowWindow from CXtFlatTabCtrl it must be do new calc
(same as in OnSize i think ).

    Jimmy