Gfortran problems in yosemite

Hi All, I would be most grateful for any assistance with the following issues with NONMEM. I'm using a mac (2012) and I've just recently upgraded to yosemite. The problem is that NONMEM has stopped running on my laptop since upgrading. This is fairly typical after an upgrade in mac and is usually a problem with gfortran compatibility which should normally be resolved by uninstalling and re-installing gfortran with the following command: sudo rm -r/usr/local/gfortran/usr/local/bin/gfortran I've tried re-installing the 5.2 version of gfortran which is compatible with yosemite ( https://gcc.gnu.org/wiki/GFortranBinaries#MacOS). I then tried running NONMEM but I'm getting the following errors: WARNINGS AND ERRORS (IF ANY) FOR PROBLEM 1 (WARNING 2) NM-TRAN INFERS THAT THE DATA ARE POPULATION. (WARNING 13) WITH USER-WRITTEN PRED OR $PRED, NM-TRAN CANNOT APPEND THE MDV DATA ITEM.Note: The following floating-point exceptions are signalling: IEEE_INVALID_FLAG IEEE_DIVIDE_BY_ZERORecompiling certain componentsMUMODEL.f90:67:10: USE FSIZES, ONLY: F_PC,F_PG,F_LVO,F_LVS 1Fatal Error: Cannot read module file ‘fsizes.mod’ opened at (1), because it was created by a different version of GNU Fortrancompilation terminated.PRPNM.f90:58:10: USE PNM_CONFIG, ONLY: PNM_UPAR,M_IDEFD,M_IDEFA,M_EL,M_TQ,M_DAC,M_DPC 1Fatal Error: Cannot read module file ‘pnm_config.mod’ opened at (1), because it was created by a different version of GNU Fortrancompilation terminated.Building NONMEM Executablegfortran: error: temp_dir/MUMODEL.o: No such file or directorygfortran: error: temp_dir/PRPNM.o: No such file or directory No nonmem execution. It appears there are still problems with gfortran. Would anyone be kind enough to assist? My other question: Is there a way to prevent future upgrades on the mac interfering with NONMEM? Kind Regards, AdedejiPhD student, UCL.