Try Chrome if you use something else, it works for me.
I have a little problem too, I don't know how to explain it, so here's a picture: http://i.imgur.com/LFvmD85.png
Mouse hovering over 'Idle' and 'Shoot' works, but clicking don't, I have to press Enter to choose.
I am using Linux and Firefox, on Chromium it's OK.