White smoke ... I succeeded in creating the Monte Carlo executable that links the CERN library and the Tcl/Tk .a and .h files. I just got rid of a macro that is proprietary for Sun Unix but it's deleterius on Linux/Suse. The culprit is " -Df2cFortran". This option was in the list of the CFLAGS and CXXFLAGS. I realized it was junk when I launched "make -p". This is a left-over from the installation procedure for Sun. It's just amazing that "make" did not complain about it ! Thank you all for assisting me through this nightmare. Maura