[CONNECT C++] Sync ComboBox Dialog Item

I have a MSDialog item list that contains several text items and a ComboBox.  All items have access strings that are published global variables.

The code to sync the dialog that contains that item list is pretty simple...

void		Utilities::SynchToolSettings		()
{
  MSDialogP     toolSettings = mdlDialog_getToolSettings ();
  if (toolSettings)
  {
    mdlDialog_itemsSynch (toolSettings);
  }
}

When I issue SynchToolSettings, all the text items update with their current values, but the ComboBox doesn't respond.  Do I have to write something in the ComboBox hook function to persuade it to sync?