Analysis results differ with different versions of g77 compilers?

[Lu, Yuan]

Hi there,

I have a strange problem: When I copied the Fortran programs 
(compiled with GNU F77 2.96 20000731) from a
Red Hat 7.3 system to a Red Hat 9.0 system, and
run the programs, I got one results set.

After I recompiled the same Fortran programs with gcc 3.2.2 20030222
on the same Redhat 9.0 system , and ran the same programs with same 
input data set as above, I got a different results set. Usually the 
results differs from the 4-th decimal point. 

Any body knows what's the reasons why I got different results? 

Many thanks.

Yuan