i have a similar annoying issue with the randomly rotating phone app.
i've set it to portrait only, and what happens is when i get the phone out of lock with the side switch, press the phone shortcut, the app launches in portrait, but right away it flips to landscape, regardless of the keyboard and the phone orientation, then when i press the 'keypad' button, it goes back to portrait. other applications shows there is no problems with the accelerometer either...

can post up a video of this happening if it gives a better idea.

i just want the entire phone app to stay in portrait and never be in landscape, seems this isnt working at the moment.