any idea why this: http://www.ci.uchicago.edu/~benc/fmri-tutorial/4-combine-img-hdr-type.swift hangs for me after running all four reslice commands? A similar (i.e. intended to run the same jobs) workflow is in http://www.ci.uchicago.edu/~benc/fmri-tutorial/3-compound-procs.swift and runs fine. --