Sorting Grid Columns while Grouped Scrambles Rows

Running the TMS GroupDemo program   (no Livebindings as best as I can see)...    (still occurring with 15 Nov release)

1.  Clicked the Group button
2.   Selected the Close All Nodes button
3.   Clicked the open (plus sign) button for the 'Ferrari' row, and then same for 'Alfa Romeo'
4.   The Ferrari Spider was the last visible row on grid at this point  (in other words, the group child rows fell across the page boundary)
5.   Clicked the header of the CC column to sort it.
6.   Ferrari Group is now out of sync, with header and footer on first page (as if closed, but still showing  minus sign icon), and the child records appearing later on second page within another group.
 
7.   Scroll page to next page, and then back to top of grid;    Click CC column header again to toggle to decreasing sort order.
8.   Get "List index out of bounds (153).
 
I had sent this as a support question on 2 November.   Disappointed that I received no response other than the auto-response when first sent.  Guess I need to report it here.