I would like to let Mac users know that if you have been seeing blurred lines, there is a solution! You'll need the latest version of Adobe Acrobat and you have to open the pdf file instead of using preview.
Go to 'file' and then clicked 'open with' and select 'Adobe Reader 10.1.0'.
I would like to thank Ashleigh for being a God-send! Check out her blog for more info.... http://www.ashleigh-educationjourney.com/2011/10/pdfs-macs.html