The immediate fix is to tell Lightroom to rotate the photo either clockwise or counterclockwise, whichever will fix the problem.
You can select all the photos affected, and then in the Photo menu select (I'm not sure of the exact words because I am at work) "Rotate Clockwise" or "Rotate Counterclockwise".
Does your camera have a menu option called "Auto Image Rotation" or something similar? My D300 has that option in the Setup (wrench) tab. If so, turn it ON.
Yes - thanks. Got it done.