I know that pulling (then replacing) the card on the 721 causes a reboot, but I also see that pressing the power button and holding it for about 8-10 seconds results in a reboot as well. Is pulling the card somehow better? It would seem that pulling the card could eventually lead to a scratched/dirty/defective card, whereas holding down the power button would be more benign. So why do so many people (including tech support) tell you to pull the card for a reboot?