[f2py] differences in log and exp between compilers

hi everybody
I have a doubt about some functions, specially log and exp

I'm in process of rewrite a program writen with microsoft fortran
compiler using f2py

I have succesfully rebuild many functions but any function wich use
log or exp has diferences with the original program
I'm using the gnu compiler and I want to know if anybody using
differents compilers (intel, compaq, microsoft) have found the same or
there is something wrong
in my code

thanks in advance