problem with CMFCOutlookBar hiding

hi
i make a new mfc sdi project as if embed a CMFCOutlookBar in this by wizard.
two category is added by wizard in pane.

tree.Create(dwTreeStyle, rectDummy, &bar, 1200);
bNameValid = strTemp.LoadString(IDS_FOLDERS);
ASSERT(bNameValid);
pOutlookBar->AddControl(&tree, strTemp, 2, TRUE, dwStyle);

calendar.Create(rectDummy, &bar, 1201);
bNameValid = strTemp.LoadString(IDS_CALENDAR);
ASSERT(bNameValid);
pOutlookBar->AddControl(&calendar, strTemp, 3, TRUE, dwStyle);

i comment AddControl and delete two category

tree.Create(dwTreeStyle, rectDummy, &bar, 1200);
bNameValid = strTemp.LoadString(IDS_FOLDERS);
ASSERT(bNameValid);
// pOutlookBar->AddControl(&tree, strTemp, 2, TRUE, dwStyle);

calendar.Create(rectDummy, &bar, 1201);
bNameValid = strTemp.LoadString(IDS_CALENDAR);
ASSERT(bNameValid);
// pOutlookBar->AddControl(&calendar, strTemp, 3, TRUE, dwStyle);

i add custom category

pdlgServers=new CServersDlg(&bar);
pdlgServers->Create(IDD_DIALOG_SERVERS, &bar);
bNameValid = strTemp.LoadString(IDS_SERVERS);
ASSERT(bNameValid);
pOutlookBar->AddControl(pdlgServers, strTemp, 2, TRUE, dwStyle);
pdlgServers->ShowWindow(SW_SHOW);

but this pane be hide.
what is my bug?