I haven't seen any information from Apple about the app update data loss bug. I also haven't seen a solid reproducible case and/or workaround. It has all the markings of a bug that's going to be hard for anyone not named Apple to test and narrow down to a reproducible case. Perhaps we can pool our experiences (and those of your customers) and see if a pattern emerges. When you lost data... 1) Which device were you using: OG iPhone, iPhone 3G, or iPod Touch? 2) What version of firmware were you using at the time: 2.0.0 or 2.0.1? 3) What version of iTunes were you using? 4) Which platform did you update the app from: The iPhone/iPod Touch, iTunes Mac, or iTunes PC? 5) Did you update a single app, or did you update a batch of apps at the same time using Update All?