Did you try with an other browser ? I used to have the same problem, I think it's an update issue. Try to update your browser.
The only solution I found to avoid those 8 was to remove all my checkbox on the PDF ...
EDIT: It seems that the problem come from the PDF viewer, did you try to save the PDF and open it with Acrobat Reader ?
ankur Le 06/03/2014 à 09:23 Its worked for me. Thanks for your solution.