I reported this here (http://www.sqlnotes.net/drupal5/index.php?q=node/2623) but it was not answered. This was present in the W10 update and still present in W10 portable, but less so and with a variation.
1. Keep on adding TLIs until you fill the screen.
2. Now add a few sub items, all at the same level.
3. Now add a sub item to the sub item (I use tab to do that).
4. Keep on adding sub items. See? You lose the item off screen.
This is VERY frustrating. I can't use this for work because it seriously interrupts my data input workflow.
Jon
P.S. This is not present in W5. I think this was re-introduced in subsequent versions. Some were worse than others.