Recently a user of one of my apps reported that all her data was lost when she updated the app. I think this is a long shot, but is there anyway for me to inspect her 'documents' folder within the app on her iPad? Or a way for her to send me her document folder so I can see what's going on and hopefully salvage the data?
If she is a fairly technically capable user, you could have her use PhoneDisk http://www.macroplant.com/phonedisk/ to mount your app's sandbox and inspect the Documents folder.