Upgrading Android Version cleans application data?

I've received a strange bug report:

After a OTA update of the SO from 2.1 to 开发者_StackOverflow2.2 the SharedPreferences have been wiped, thus making my app return to the 1st time screen.

Is this a normal behaviour, wipe of the SharedPreferences on system update although maintaining the app installed?

Thanks

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Shared Preferences data will remain.

Kindly check the following link which provides a good analysis of your problem.

http://groups.google.com/group/android-developers/browse_thread/thread/246aae66e0caf302/908be552b1d86158?lnk=gst&q=Shared+Preferences#908be552b1d86158