I notice this error/bug report is 2 months old and the latest version of Jetpack was released 5-1-13. I also noticed that there's a whole lot of major sites showing this error. To your knowledge (and I realize it might be hard to tell), does this mean they just have updated? Or was the error not fixed in the 5-1-13 release?
These are major, high traffic sites I'm seeing this on, including http://www.addictinginfo.org/ and one would think they would have noticed.