After I rebooted my linux 64 bits PC this morning, chimera crashes the machine. I tried older versions of chimera ... same result :-( How can I fix that situation ? Jean-Fran�ois M�n�tret, PhD Boston University School of Medicine Physiology and Biophysics Department 700 Albany Street W315 Boston, MA 02118 Email: menetret@bu.edu Mailing address: 715 Albany Street