Well, first of all I am very sure that I don't know much about gfortran or the commands related to it, as I have never used it before. I have always been using g77.
Regarding complaints, as terry-duell wrote, they are warnings and not unusual. But at the end an executable file should be produced, which does not happen. These codes comprise of equations which I am using to calculate some results. They are not any technical codes as such.
Regarding this other system, I have no idea what it is except that it is an Unix system and I connect to it through SSH client. But I tried to find which f90 compiler it has, using following command
and it said that "f90 - invokes the Compaq Fortran 90 (formerly DIGITAL Fortran 90) compiler
f95 - invokes the Compaq Fortran 95 (formerly DIGITAL Fortran 95) compiler
f77 - invokes the Compaq Fortran 90 (formerly DIGITAL Fortran 90) compiler
f77 -old_f77 - invokes the Compaq Fortran 77 (formerly DIGITAL Fortran 77)compiler"
May be this could be of some help.