I will give a try to Restoring those files and submitting them. Thanks for explaining.
RE "Rogue" pdfs: I don't know what more to really say. I know it sounds unlikely and illogical. I've been using ZA for many years and my online experiences and habits are usually running in cautiously vigilant mode.
I'm a graphic designer and create websites -- but am not a programmer. From a simple article I just looked at, I created an example of how a PDF download screen can appear by simply visiting a page. Granted, my sample does not download automatically with ZA, but one doesn't need to click on any link to see the PDF Run/Save prompt.
http://www.creativedigitalmasters.com/za/zapdf.htm (example I created)
The only user interaction I can recall about the PDF issues... was that I was reading some news/commentary-ish sites only to read the article on that page. If hackers by chance are creating malicious code if a mouse happens to hover over (as does when moving mouse to the right hand scroll bar -- often ads are very close to the right edge).