Steps to recreate:
1. Open Browser A to your T5 application.
2. Search for a record with an editable grid with more than one row.
3. Sort the grid by Column X.
4. Open Browser B (new tab/window on the same machine)
5. Search for the same record as step 2
6. Sort the grid by Column Y (any sort which gets the rows in a different order)
7. Save the record in Browser A (it has the original sort order).
Tapestry saves the row data to the wrong objects and effectively 'scrambles' them.
This issue is similar to issue:
Please let me know if there are any issues recreating this issue or if additional information is needed.