Oh, thanks, OP. I have been meaning to post something about this.
I did find a work around though. If your stroppy 6yo, having been told she can't play on your phone, proceeds to try and hack her way in, guesses the pin code wrong 8 times and thereby wipes all data off the phone, then you have to reinstall everything. When you reinstall the app, you start with a clean 'active' list, and it takes a little while to get to annoying proportions again.
Not necessarily an approach I would recommend - next time I might not be so restrained in my reaction.