Hi Matthew: --- On Wed, Mar 14, 2012 at 12:13 PM, Matthew Hobbs <matthew.hobbs@xxxxxxxxxxxxx> wrote: | gfortran44 -L/usr/lib64/atlas -fexternal-blas -lf77blas matmultest.f90 -o matmultest_f77blas | /usr/bin/ld: warning: libgfortran.so.1, needed by /usr/lib64/atlas/libf77blas.so | may conflict with libgfortran.so.3 \-- Could you try installing and using the compat-libgfortran-41 package that provides libgfortran.so.1? SK -- Shakthi Kannan http://www.shakthimaan.com