I just installed the plugin and found that the "EDIT CSS" button does not appear.
I found that there is a CSS property "overflow: hidden;" in the id "csstab" that when I disable it, then the button appears...
Please fix :)
the second problem is that now when I can see the button and press it, I can't work with it, it's impossible to work with.
It's a great plugin and I'd love to help improve it,
so call me and I'll help.