Hi Nat, Will replicate and send you the information. Its unrelated to Ramachandran restraints as it occurs intermittantly when doing just regular tasks. I can always tell early as it never seems to get past the first steps of the refinement protocol - in essence - it never starts xyz refinement. Just sits there. I abort and restart and it then goes fine. I'm running Mac OSX 10.8.4 Joe ______________________________________________________________________________________ Joseph P. Noel, Ph.D. Arthur and Julie Woodrow Chair Investigator, Howard Hughes Medical Institute Professor, The Jack H. Skirball Center for Chemical Biology and Proteomics The Salk Institute for Biological Studies 10010 North Torrey Pines Road La Jolla, CA 92037 USA Phone: (858) 453-4100 extension 1442 Cell: (858) 349-4700 Fax: (858) 597-0855 E-mail: [email protected] Publications & Citations: http://scholar.google.com/citations?user=xiL1lscAAAAJ Homepage Salk: http://www.salk.edu/faculty/noel.html Homepage HHMI: http://hhmi.org/research/investigators/noel.html ______________________________________________________________________________________