A company that commonly sends us e-mail, has recently sent 5 different PDF files all version 1.5. I cannot open them from any computer. All computers have acrobat reader 9 installed. No computer has ever had a problem opening a PDF. What happens is that the outline of acrobat reader opens, but the center is just the background of the dekstop, and immediately goes to not responding. No amount of time will change this. I am aware of Acrobat reader X (10), but will only upgrade to this if it is only answer.