Umbridge, dementors, spy in Order?

[mugglemonkee]

No: HPFGUIDX 72458

I was wondering the same thing about the spy, but for a different reason. I was 
thinking about when Lucius was talking to Harry and Arthur in the MOM. 
Lucius looked at the Dept. of Mysteries door and said something like surely 
your not working here to Arthur. At first read I thought it was him being his 
usual nasty self, but the 2nd time around I thought maybe he KNOWS Arthur 
has been guarding that door. And if he hasn't seen him, the only other way he 
could know is that someone has leaked information.

Any thoughts?