In /source/geometry/solids/STEP/src/ExpDict.cc, at line 580 the return type is missing in the prototype of TypeDescriptor::IsAggrType. I added "int". In /source/geometry/solids/STEP/include/dirobj.h, line 62, I had to change "#include <stat.h>" to include a path : "#include <sys/stat.h>" The problem is also present in GEANT4.1.
You're most likely not compiling with the g++ compiler version we support, i.e. egcs-2.91.66 (egcs-1.1.2) which comes with Red-Hat 6.1. We do not support g++ 2.95.X in Geant4 1.1. Thanks for reporting this, anyway.