I encountered the following error if I:
1. fill list
2. Swap channels or add grouping
3. call Nodes.Clear ()
4. fill again
while the list is filled correctly, but when you try to change the column width or swap them, I get an exception:

Unable to bring the type of object "Nevron.UI.WinForm.Controls.NTreeListGroupByNode" to type "Nevron.UI.WinForm.Controls.NTreeListHeaderItem".
or
Unable to bring the type of object "Nevron.UI.WinForm.Controls.NTreeListNode" to type "Nevron.UI.WinForm.Controls.NTreeListHeaderItem".

And the second question, if I added a grouping of fields and add new entries to the list, then they are added without regard to factions, ie, the end of the list.