I've just done a fresh install of SooperLooper (1.6.16) on a MacBook Air running 10.6.7 and the SooperLooper GUI doesn't seem to be able to connect to the server.
I started by just running the GUI directly, but running from the console gives:
stuart@wopr: /Applications/SooperLooper.app/Contents/MacOS$ ./sooperlooper
Copyright 2007 Jesse Chappell
OSC server URI (network) is: osc.udp://wopr.org.au:9952/
And then the GUI:
stuart@wopr: /Applications/SooperLooper.app/Contents/MacOS$ ./slgui
slgui: our URL is osc.udp://wopr.org.au:10845/
execing: '/Applications/sooperlooper -q -U osc.udp://wopr.org.au:10845/
-p 9951 -l 3 -c 1 -t 60 -m "/Users/stuart/.sooperlooper/default_midi.slb" -D no'
execvp(/Applications/sooperlooper, -q, -U, osc.udp://wopr.org.au:10845/
, -p, 9951, -l, 3, -c, 1, -t, 60, -m, /Users/stuart/.sooperlooper/default_midi.slb, -D, no) failed with error 2!
slgui: remote looper is at osc.udp://wopr.org.au:9951/
version=1.6.16 loopcount=3 id=1302763445
but treating the engine URL as osc.udp://:9951/
The GUI very quickly comes up with a "Lost Connection" dialogue box.
I must admit at this stage that I'm very new to Macs, so I may be doing something pretty obviously wrong. Jack seems to be running okay though, and Ardour works just fine.