SetCloseSubMenuOnClick - redraw problem

Here's a popup-gallery (SetCloseSubMenuOnClick = FALSE):

 

"Clear" has been pressed, but the list is not redrawn until I hover it with the mouse!

 

When I press "Clear" the following code is executed:

 

void CMainFrame::OnGalleryClear()
{
 for (int i = 0; i < m_pItems->GetItemCount(); ++i)
 {
  CControlGalleryItem *pItem = DYNAMIC_DOWNCAST(CControlGalleryItem, m_pItems->GetItem(i));
  ASSERT(pItem);
  if (pItem)
   pItem->SetChecked(FALSE);
 }
}