Yes I know I should be using a rebar but I am not. So please don't advise me to use a rebar. I use the following code:

CRect rect;
int nIndex = m_wndToolBar.GetToolBarCtrl().CommandToIndex(ID_SYSTEMCOMBO);
m_wndToolBar.SetButtonInfo(nIndex, ID_SYSTEMCOMBO, TBBS_SEPARATOR, 125);
m_wndToolBar.GetToolBarCtrl().GetItemRect(nIndex, &rect);
rect.top = 1;
rect.bottom = rect.top + 250; // drop height

m_SystemCombo.Create(CBS_DROPDOWNLIST | CBS_SORT | WS_VISIBLE | WS_TABSTOP | WS_VSCROLL, rect, &m_wndToolBar, ID_SYSTEMCOMBO);
m_SystemCombo.SetItemHeight(-1, 19);

if(fMain.CreatePointFont(80, "MS Sans Serif", NULL))
{
m_SystemCombo.SendMessage(WM_SETFONT, (WPARAM)(HFONT)fMain, MAKELPARAM(TRUE, 0));
}

And initially it showed its ugly mug nicely on the toolbar. After submitting my code someone tested it there and there was just an empty space on the toolbar the size of the missing control. After playing around I now don't have the combo box showing.

What the dickens could be causing this to happen?