if you freshly installed Audio Hijack while Remote Buddy was running: 
please relaunch Remote Buddy.

if you had Audio Hijack installed before you launched Remote Buddy: 
please make sure AH was launched at least once and that it resides on 
a volume that is mounted at Remote Buddy start time.

if that does not lead you to the solution, either: please use 
LSRefresh (from the Blog) to update your Launch Services Database 
record for that application, then (re)launch Remote Buddy.

All Remote Buddy Behaviours use the OS X Launch Services for automatic 
app detection. So, if an app is not listed in the LS Database, Remote 
Buddy will not load the associated Behaviour.

Best regards, 
Felix