Then, I guess the "Sep 30, 2011 at 8:53pm", moment of your failed attempt at collecting a power, was the time expressed in your own time zone (I checked it against the time of the post in which you complained about not being able to get a power you found). If so, then it converts to "Sep 30, 2011 at 6:53pm" in Reikjavik.
And there you have it! You acquired a power on Sep 30 at 12:13 a.m. (Reikjavik time) and attempted to acquire another one on Sep 30, 2011 at 6:53pm (Reikjavik time), in other words, during the same Reikjavik day! That's why you couldn't acquire the latter power!
Elementary my dear WHaDson...