The other day while sitting in Starbucks working on my iPod touch 4 (v. 5.0.1) I noticed that at the top of the screen, in place of the usual time of day, there was a white padlock icon, as if some sort of lock or security function was active. I don't ever recall seeing such an icon at that screen location before; I wasn't in an app that required a password to use, and though I was logged in to the wifi I wasn't doing anything online (including mailing or downloading). The icon stayed on the screen even when I got in my vehicle in the parking lot. It eventually went away & was replaced by the time again. Any ideas?
Are you referring to the orientation lock? I certainly didn't knowingly engage it, and I can't see how I even accidentally tripped it. Besides, at some point it reverted to the clock, and I never even accessed the orientation lock feature at all.
I just engaged the orientation lock: it showed an indicator in the form of a padlock with a curving arrow around it to the right of the time, and to the left of the battery, bluetooth icons in the upper right-hand corner. Not at all the same thing as the simple centered padlock symbol. Haven't seen it since then, either.