[R] .C and .Fortran

[Filippo Monari]

Hi,
I'd like to know what is the difference between the functions .C() and 
.Fortran.
I noticed that by enclosing my F90 subroutines in modules .Fortran() 
can't find them any more in the load table, while .C() still can. I also 
checked that the subroutine was loaded with the is.loaded() function...
So can anyone explain to me the difference and which is better to use?
Thanks in advance,
Filippo