Weird data grid behaviour

[Gerry Orkin]

Weirdness going on here with LC commercial 6.5.2 and all versions up to 6.6.2:

1) I drag a new data grid onto a stack
2) in the object inspector I make the datagrid a form datagrid (not strictly relevant as the problem happens with table datagrids too)
3) in the datagrid templates substack I see two cards, id 1002 and id 1005. I've never seen that before!
4) on card id 1002 I have ONLY the _DataGridTemplateInstructions_ group
5) on card id 1005 I have the expected row template group and it's contents
6) when I click the Row Template... button in the datagrid's inspector I see what looks like card id 1005 (I can see the row template)...but the title bar of that window says card id 1002. 
7) any changes I make to the row template on that card are NOT shown in the datagrid itself.
8) if I try to associate the row template on card id 1005 with the datagrid (e.g. set the dgProps["row template"] of group "Datagrid 1" to the long id of group id 1006 of card id 1005 stack "Data Grid Templates 1402184271384") I get no errors in the msg box but nothing changes. 

Arghhhhh. Help!

Gerry