Weird! –I posted another reply a couple of weeks ago, listing the [few] plugins I had installed. It seems to have disappeared.
Anyway, I've just disabled ALL my other plugins, reverted to the default '2012' theme and tried quick editing a post that was part of a series and Organise Series lost the series info again. So I think we can safely say that this is not a case of "user error". The plugin is definitely broken –at least for some users.
Here's what I'm seeing:
1: Select a post that is part of a series and hit 'Quick Edit':
2: The problem seems to stem from the fact that the Quick Edit form does not populate with the series info in the 'Series' popup menu on the left, although it is correctly listed as part of a series in the 'Series' textarea on the right :
3: If changes are made [In this case I changed the title of the article] and saved, post will have been removed from series:
In addition, trying to 're-insert' the post back into the series via the Quick Edit form is also broken. I added it back in at its original position as part 17 of 20. however it was added at position 20 and the original posts 18-20 renumbered downwards to fill the gap. I was only able to re-insert the post in its proper place and fix the other posts through using the full edit screen.