I was trying to install SciPy today after a successful numpy install and it went well until it got to the fortran compilation of dfftpack. Below is an exerpt of the error. Anyone know what's going on? running build_clib customize UnixCCompiler customize UnixCCompiler using build_clib customize GnuFCompiler customize GnuFCompiler customize GnuFCompiler using build_clib building 'dfftpack' library compiling Fortran sources Fortran f77 compiler: /usr/bin/g77 -g -Wall -fno-second-underscore -fPIC -O3 -funroll-loops -march=i686 -mmmx -msse2 -msse -fomit-frame-pointer creating build/temp.linux-x86_64-2.3 creating build/temp.linux-x86_64-2.3/Lib creating build/temp.linux-x86_64-2.3/Lib/fftpack creating build/temp.linux-x86_64-2.3/Lib/fftpack/dfftpack compile options: '-c' g77:f77: Lib/fftpack/dfftpack/dsinqi.f Lib/fftpack/dfftpack/dsinqi.f:0: error: CPU you selected does not support x86-64 instruction set Lib/fftpack/dfftpack/dsinqi.f:0: error: CPU you selected does not support x86-64 instruction set Lib/fftpack/dfftpack/dsinqi.f:0: error: CPU you selected does not support x86-64 instruction set Lib/fftpack/dfftpack/dsinqi.f:0: error: CPU you selected does not support x86-64 instruction set error: Command "/usr/bin/g77 -g -Wall -fno-second-underscore -fPIC -O3 -funroll-loops -march=i686 -mmmx -msse2 -msse -fomit-frame-pointer -c -c Lib/fftpack/dfftpack/dsinqi.f -o build/temp.linux-x86_64-2.3/Lib/fftpack/dfftpack/dsinqi.o" failed with exit status 1 Thanks for your help.