I am a Dropbox user. I have until recently been almost strictly a Google Chrome user. The PDF seamless behavior I have been seeing in Chrome is like this: 1. If I click on a search engine result for a PDF, I see the PDF opened in the browser. 2. If I click on Download at Dropbox, the PDF is downloaded to my PC. On installing Firefox, the behavior I saw was like this: Whether I clicked on a search engine result or Download at Dropbox, I saw the PDF opened in my browser. When I changed the Action for Portable Document Format (PDF) (application/pdf) and Portable Document Format (PDF) (application/binary)to "Save File", the PDF downloaded to my PC. But so did search engine links. I seem to have fixed the issue by making my settings like this: 1. Action for Portable Document Format (PDF) (application/binary) to "Save File" 2. Action for Portable Document Format (PDF) (application/pdf) to "Open in Firefox" Fingers crossed. ??? I was wondering why it wasn't set up this way on installation.