Oddly enough, I was facing the problem that the signature used to get reset from none to like dushie above everytime I restarted the playbook, but it seemed to have resolved on its own. I bought the tapatalk 1 for playbook, but somehow more comfortable with the colors in tapatalk 2, which I hear is not coming to Playbook officially due to some APIs not being supported, but sideloading works fine, so not sure what's the problem.