one thing that occured to me after recently getting a 40in LCD and a 42in plasma. (returned LCD, got plasma)
They were packaged differently. The LCD was like a smaller computer LCD in the way it was in the box. Thick packing material all around the front and back of the monitor. The front (glass) and rear was well supported.
The plasma was in a thicker box (almost twice as thick) there was heavy packing material on the top and bottom of the panel but the center area was just air. (where the glass is.)
The plasma is well supported if transported upright. but if on the sides it could be enuf to cause the screen to flex and crack.