I would say that's not really convenient to have the same shortcut for lock AND unlock.
using plus! for few years, i used to "hit" the "lock" shortcut" if needed, without to check if msn was blocked already or not.
now if I hit the shortcut with msn already blocked, I've got a pop-up for password prompt, an awkward pop-up...
AND... (there is more..)
the double-click function HAVE to be optional, there is so many thing to double-click in some systray, that the same awkward pop-up could... pop-up.
NB :I'm French, excuse my English
EDIT : sorry I didn't see the 2nd page