I had the same problem. Wanted to change default android account, but the "Factory data reset" under "Configurations - Privacy" not works. The operation finish normally, but the phone only reboot with the same account and settings.
The good news is that I found another way to change the account...
"If you have rooted your Android device, you can change the default account without resetting your phone by deleting the "accounts.db" file in the" /data/system" folder using the Root Explorer app (see Resources) available from the Google Play market. Once deleted, your device will guide you through the Google account setup wizard and all your applications will remain installed."
Done this, it worked!
Thank Jason Spidle. Tip found on the page: http://smallbusiness...roid-56066.html