There are known problems trying to access PDF's using Mozilla Firefox ( versions newer than 3.0.5) and Adobe 9.X
When clicking on the PDF icon to open the article you may get a blank screen with "Done" at the bottom.
We were able to fix the problem by going into Firefox "tools" and "applications" and changing the association for Adobe Acrobat from "plugin" to "Adobe Reader" as per screen shot instructions from Mozilla at the following link.
http://support.mozilla.com/en-US/kb/Opening+PDF+files+within+Firefox
Another alternative to this is to use a different browser such as Internet Explorer.
