Not working in FF 3.6.18 Noté 1 sur 5 étoiles

I just installed this, and there's no sign of it.
There are no resize indicators and I can't resize any textareas.

It hasn't been updated since 2006, so it appears to be dead. I know this extension isn't needed in FF 4+, but there's still a lot of 3.6+ users.