This is weird.
I open a particular file from the web and the page starts to slowly blur out of focus.
Here is a screen capture if it doesn't happen for you:
selecting some text with the ar will refocus it for a few seconds and then it reblurs..
i'm also attaching the original file
Just as weird.
When I opened pdf-files with Reader 9.1 on my Vista 64-bit, the program window started to become speckled, little blue spots all over the window so that it quickly became unreadable. If the window was redrawn (after being covered or partially when the cursor was over a button) it was clean but quickly it became unreadable again. Especially quickly if it was moved. And this "disease" spread to other programs running and to the desktop as well. Also after closing down Reader 9.1
Rebooting was the only cure.
So I uninstalled Reader 9.1, went to adobe.com, download, other OS, selected Windows XP SP3 to be my OS and asked for Reader 8.1.3. It works fine with Vista 64 and creates no speckles.
i was having the same problem and i fixed it by uncheking use 2D graphics acceleration in preferences->page display