Using an older Blackberry to browse, but I assume this would happen on other devices as well.
The Send button is unreachable on the private message pop-up. After the introduction of the adding pictures feature, it used to be the case if I zoomed in at all, now it seems to be happening all the time.
I would recommend placing the Send first, since it is a mandatory use button, and the picture add second, as it is an optional use button.