The profile cannot change if the device is holstered, locked, powered off, or if keystroke injection is set to Disallow (e.g. BES IT Policy). This limitation is imposed by RIM's API restrictions.

Profiler will notify you by vibrating that a profile change is trying to happen, and when you do unholster/unlock the BB, it will then complete the change.

At one time I even removed my sleeper magnets from my holsters so that profile scheduling applications would work for me around the clock (I don't lock my device nor am I on BES), but later I decided that I would live with unholstering after a notification.