When the panel is attached, you can highlight a rule with the mouse and copy/paste it to another class via ctrl/c > ctrl/v
When the panel is detached, if you highlight a rule with the mouse, it instantly causes the highlighted rule to de-highlight, and produces a new, blank rule underneath it. You cannot copy/paste, because nothing is selected.
I reported this on the Bug submission on the home page, but wanted to see if anyone else can confirm. Windows 7 machine.
Here's a video to show the problem...
http://thelightwavegroup.com/images/ExaVid.mp4