Getting no arrows on ListBrowser column titles

I'm currently creating my first tool that uses BOOPSI Gadgets. The layout looks like this: Screenshot in my cloud

I've set up the ListBrowser so that it sorts the first column "Old name" when clicked on its title. This works so far. But I've also set that arrows should be displayed on this column to show the current sorting direction visually - and this works not.

The ColumnInfo is allocated like this:

m_pColumnInfo = AllocLBColumnInfo(2,
                                  LBCIA_Column, 0,
                                  LBCIA_Flags, CIF_WEIGHTED,
                                  LBCIA_AutoSort, TRUE,
                                  LBCIA_SortArrow, TRUE,
                                  LBCIA_SortDirection, LBMSORT_FORWARD,
                                  LBCIA_Title, "Old name",
                                  LBCIA_Weight, 50,
                                  LBCIA_Column, 1,
                                  LBCIA_Flags, CIF_WEIGHTED,
                                  LBCIA_Sortable, FALSE,
                                  LBCIA_Title, "New name",
                                  LBCIA_Weight, 50,
                                  TAG_DONE);

And the ListBrowser set up is:

...

LAYOUT_AddChild, m_ppGadgets[GID_LISTBROWSER] = NewObject(LISTBROWSER_GetClass(), NULL,
  GA_ID, GID_LISTBROWSER,
  GA_RelVerify, TRUE,
  GA_ReadOnly, TRUE,
  LISTBROWSER_ColumnInfo, (ULONG)m_pColumnInfo,
  LISTBROWSER_ColumnTitles, TRUE,
  LISTBROWSER_TitleClickable, TRUE,
TAG_DONE),

...

What did I miss to get the arrows displayed?