I seem to have the same problem:
I installed the public alpha driver, rebooted, waited 2 minutes and then plugged in the USB cable. Nothing happens. All I see in the Console.app:
Code:
30-01-13 08:25:22,056 com.apple.launchd[1]: (com.displaylink.displaylinkmanager[10361]) Job specified non-existent working directory: /Library/PrivilegedHelperTools/DisplayLink
30-01-13 08:25:22,057 com.apple.launchd[1]: (com.displaylink.displaylinkmanager[10361]) Job failed to exec(3). Setting up event to tell us when to try again: 2: No such file or directory
30-01-13 08:25:22,057 com.apple.launchd[1]: (com.displaylink.displaylinkmanager[10361]) Job failed to exec(3) for weird reason: 2
30-01-13 08:25:22,088 com.apple.launchd[1]: (com.displaylink.displaylinkmanager) Job should be able to exec(3) now.
30-01-13 08:25:22,089 com.apple.launchd[1]: (com.displaylink.displaylinkmanager) Throttling respawn: Will start in 5 seconds
30-01-13 08:25:25,282 com.apple.launchd.peruser.501[261]: (com.displaylink.useragent[298]) Exited: Terminated: 15
I have attached the results of the DisplayLink information tool.
MacBook Air 13"
Mid 2012
Mountain Lion 10.8.2