I'm going to try and explain this the best I can.
We recently upgraded computers and upgraded to autocad LT 2012. We used to use autocad LT 2011. With the only system I used acrobat X standard to print pdf's. I'm using the same program with the new system/version of autocad.
It used to be that when I was at the standard autocad plot dialog box under "Drawing Orientation" I could select Portrait or Landscape. When I did the is the litte prview box with the paper size would rotate and the drawing rotate with it. So if I changed the orientation to landscape the drawing would plot to pdf correctly.
Now when I change the orientation the paper changes in the preview but the actual drawing doesn't rotate to fit the page orientation. I'm not sure if that makes sense or not.