If this is a Mac permissions problem, I have a couple of saved messages to read
Mac and Root User http://forums.adobe.com/thread/879931
-and http://forums.adobe.com/thread/940869?tstart=0
And a couple other messages that MAY help (don't know, I'm Windows... but free to read)
Mac 10.8.3 Bug w/Encore and BluRay http://forums.adobe.com/thread/1198709
-create folder not ISO http://forums.adobe.com/thread/1216127
