Thanks for sending that. Everything *looks* fine. Also, when I processed that dset, I was running it on a Mac, as well. Sooooo.... hmmph.
Is there more text output from running the script, by any chance? Like the full output? You could email it to me or put it in the upload folder, if that is easier. That might help show some more ideas.
Another thought is: you have 4 CPUs on your computer, and you are using 4 CPUs for this SSW command-- perhaps if you have other applications running at the same time (like a web browser, which can be *quite* greedy on RAM), then memory is getting used up? If that were the case, I would expect the word "Killed" to appear in the terminal output (that is used in a technical sense when, as your OS will "kill" a process if starts asking for too much computer memory).
--pt