PDFs created with other applications (f.ex. Autocad), positioning in Adobe Acrobat (9.0, PC)

[teppol52948377]

Hello!

Why often PDFs, which are created with other applications (f.ex. Autocad), are often posited 90 degrees compared to the original, when they`ve been brought to the Adobe Acrobat (9.0 Pro, PC)? That happens every time when you open the document, even though you have saved it "correctly rotated"...