Are all the PDF icons on you HD the white icon? Did/Do you have a Beta or other version installed in side-by-side mode? If you haven't, try reassigning PDFs to Revu. Right click on a PDF icon and in the popup list choose OPEN WITH > CHOOSE DEFAULT PROGRAM... then choose Revu. If that doesn't work, and you have Adobe Acrobat Reader installed (or another PDF reader) repeat the process and assign Acrobat as the default program first (and all the icons should change to Acrobat's default), then go back again and reassign Revu as the default program and see if that "resets" the icon. Don't know if it this will work or not - but these would be my next steps. Good luck!