It seems that I have managed to get a reproducible process for an issue that has flummoxed a few other people over the past few months: http://code.djangoproject.com/ticket/14642
In a nutshell, inline formset code (which I have relatively little understanding of so far) is not protected from simultaneous edits of related items. It's insidious because it probably won't happen if you are the only user on the system testing your app in development. It's only when you get to production and many people are working on the same data. I can also confirm that this happens on the latest Django 1.3 rc1 I'm trying to go through the code now to find a way to patch it but my main reason for coming to the developers list is this: What is Django supposed to do in this case? As a user I can think of two possible user expected behaviors: one would be that my changes overwrite the previous submission. The second is that I am informed that my form was invalid and hopefully the developers have given me a new form and somehow preserved my submitted data. What is the correct behavior? -- You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@googlegroups.com. To unsubscribe from this group, send email to django-developers+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-developers?hl=en.