Black PDF Icons on desktop

Hi,
I have PDF icons on my desktoip that have all of a suddeen turned black. I also have some that are OK with the regular icon. I have no idea how to solve this problem. I have searched all over for a solution to this problem but indications on how to solve it seems all wrong. Nothing works.
The entire icon is black but the PDF logo is displayed in the bottom right corner.

It sounds like some of your thumbnails have gone away or are not being created correctly.

Try opening the folder options, View Tab, and changing some settings. Maybe going from Always show icons, never thumbnails and back will help. Or some of the other settings related to what shows up on a desktop icon.

Does changing the size of the icons make any difference? Try holding CTRL and moving the mouse wheel. Certain sizes may have good thumbnails, while others do not.

I have seen situations where the Adobe icons would not show correctly on a x64 version of Windows 7. In that situation, you needed to open the search window and point directly to the icon for it to renew. Maybe something like that would help. I also seem to remember a setting somewhere that mentions saving thumbnails with files, but that may have been a prior OS.