I've noticed on my Win7SP1 machine that I can't print pdf documents from the PDF viewer. The pdf loads fine but the there is a little animated rotating circle that just spins and won't go away. This is likely indicating that the hidden nav bar that normally appears, when you hover over the lower middle portion of a pdf, is not working in FireFox because it works fine in Chrome and IE.

If I try to print anyway I see a message window titled "Printing," the pdf view goes blank, and a blank page is printed unless I hit cancel in time. I also get an error message "The PDF document might not be displayed correctly" with the option to open in a different viewer -- which does work -- but its not zezty, its annoying. The same website using the same pdf works fine in Chrome and IE and the little Nav bar in the bottom-middle appears fine.