I had the same problem with my droid razr maxx on ICS... turns out the culprit was the HDMI settings. From the Home screen i went to system settings, then display, and the option to detect HDMI Connection had a check mark in it. Once i removed that check along with the one that auto rotates the screen it stayed in portrait mode like it is supposed to. It also stopped the web dock from showing up too. I hope this helps..