iOS App Store Updates

I posted this question in the Mac Programming forum yesterday but it wasn't moved over to here when the forum split, so I'll ask it again:

Does anyone know whether an application's entire sandbox, including any personal data/preferences that the user has entered, gets deleted every time an app is updated? This would really be a pain if it is the case, because my app involves the user entering a bunch of data over time and I would have to implement some sort of off-device synching mechanism in order to avoid having the data wiped out every time I want to update the app. I imagine a lot of other apps are the same way.

Nutter said:

I'm pretty sure that updating the app won't reset the sandbox.

Click to expand...

One would hope that would be the case, but I have heard one or two people say that their game high scores were erased after installing an update. So the question is whether the software did that on purpose or if the sandbox was erased by the update process.