Hi All, I am having some problems with my R compile and matrix.c My config setings are:- setenv CC "cc -xarch=amd64" setenv F77 "f95 -xarch=amd64" setenv CXX "CC -xarch=amd64" setenv CFLAGS "-xO5 -xlibmil -dalign" setenv FFLAGS "-xO5 -xlibmil -dalign" setenv CXXFLAGS "-xO5 -xlibmil -dalign" setenv SHLIB_CXXLDFLAGS -lCstd setenv LDFLAGS "-L/usr/local/SUNWspro/lib/amd64 -L/usr/local/SUNWspro/lib -L/usr /local/lib" I've installed a 64bit tcl/tk and readline -- Vin.Everett at cimr.cam.ac.uk JDRF/WT Diabetes and Inflammation Laboratory (DIL) Cambridge Institute for Medical Research (CIMR) Wellcome Trust/MRC Building Addenbrooke's Hospital Hills Road Cambridge CB2 2XY Tel +44 1223 763212 Fax +44 1223 762102 Mob +44 7990 966266