Yeah, I've been experiencing the same thing from time to time for something about a year so far. Furthermore, the support team members never told what actually went wrong and what's the issue source. And when I try to annotate the document inside the browser it always gets the wrong scaling frequently. For such purposes, I use other tools, like this one as an example edit-pdf.pdffiller.com It's a web-based application and it works fine through Opera when the basic PDF viewer becomes malfunctioning
