I have this problem....when I'm holding the phone straight up and then decide to got to landscape mode the phone does not recognize that I'm holding it different it there a way to speed up that transition?
Just how it is, phone that do that seem to always been slow in that transition. That is why I waited so long to get a phone that does that, but couldn't hold out any longer. If you go under the location settings you can calibrate the compass this might help a little.