Did you get it sorted out? I'm also a new user and struggling now for a couple of days... found serveral guides but none give me the end result I like... 
I'm using a 2010 MacMini with Lion installed, Harmony 1100, Plex and Remote Buddy/Calandair installed.

Out of the Box without additional tool I can control the basics of Plex, but cannot sleep the Mac Mini. 
Once I installed Remote Buddy and manually paired an mapped the ten remotes the controlls all gone, nothing works. 
Mapped it over and over again, tried in within the behavior but also as a Global Mapping... nothing only an "oink"-sound of OSX Lion 
Also reinstalled the Mac and Remote Buddy with the same results... very frustrating

If someone can provide me some help I would be very happy!

Kind regards, 
MelvinC