Code compilation with GCC and GFORTRAN

[muhammad.k.akbar]

Hello,
I have a FORTRAN code that uses some c routines. I compile it with gcc
and gfortran in RedHat Linux without any problem. Recently I bought a
laptop with Ubuntu. I have gcc and gfortran version 4.4.3 in it. When
I compile the code, I see the following warning:

warning: ignoring return value of 'fread', declared with attribute
warn_unused_result

When I try to run the executable, it does not run as expected. Is
there any library files that I am missing? Please help.

I am using the following flags:
gcc -c -O3 -DLINUX
gfortran -c -O3 -DLINUX -fdefault-real-8 -ffree-line-length-132

By the way, I have installed Intel compilers, and the code runs fine
with icc and ifort. I am puzzled!
Thanks,
Muhammad Akbar