Amtor Wopat

When I attempt to log in to Second Life on a Mac, there is sometimes a pause while everything starts up and then Firestorm quits with no visible error message. On checking the log, it seems that the first report is 'ERROR: socket_posix.cc(143) bind() returned an error, errno=48 Address already in use (48)'. Then there are lots more errors, but this one seems to be the first error from each attempt. Any help or suggestions welcome!