Hi, using a recent version of numpy/scipy from svn I get the following error when calling any of the optimize.fmin_* minimizers. tnc: Version 1.2, (c) 2002-2003, Jean-Sebastien Roy (js@jeannot.org) tnc: RCS ID: @(#) $Jeannot: tnc.c,v 1.201 2004/04/02 22:36:25 js Exp $ Adjust D1MACH by uncommenting data statements appropriate for your machine. STOP 779 In [2]: numpy.__version__ Out[2]: '0.9.6.2168' In [4]: scipy.__version__ Out[4]: '0.4.7.1620' Regards, Christian