IMHO, it's but a FF browser/Flash hiccup.
When I read this thread a few minutes ago in FF, I noticed that the friends' list below PLAY NOW was empty. The friends would show on my profile but on their profiles
I, too, noticed "invite friend".
Same in Maxthon after closing the WGT tabs of FF. It only changed when I closed all windows of FF and reloaded a WGT page in Maxthon:
- lefthand friends' list appeared,
- remove friend and write PM buttons showed.
Closed Maxthon and re-opened FF: ev'rything back to normal.