I don't even have a "Resend Email" button, I'm using 1.6.0.14. Maybe it is a new feature in 1.6.1.1
EDIT: I just checked the revision history: [*] BO : #PSCSX-2149 Add the possibility to re-send the order emails
So this "Resend Email" is a new feature, along with many other features and bug fixes with version 1.6.1.0 and 1.6.1.1
Im not running the latest version, so if you want to check it out and see what has changed to cause this issue, you would perhaps help other people.