I was compiling gcc-4.3.4.tar.bz2 package using gcc version 4.4.1, I think, but for example g++ was some older version. So I decided to compile package that included all compilers to get same version for all, and selected 4.3.4.

if /bin/sh ./libtool --tag=CC --mode=compile /home/jorma/gnu/gcc-4.3.4/host-i686-pc-linux-gnu/gcc/xgcc
-B/home/jorma/gnu/gcc-4.3.4/host-i686-pc-linux-gnu/gcc/ -B/usr/local/i686-pc-linux-gnu/bin/ -B/usr/local/i686-pc-linux-gnu/lib/
-isystem /usr/local/i686-pc-linux-gnu/include -isystem /usr/local/i686-pc-linux-gnu/sys-include -DHAVE_CONFIG_H -I.
-I../.././libgfortran -I.  -iquote../.././libgfortran/io -I../.././libgfortran/../gcc -I../.././libgfortran/../gcc/config
-I../../host-i686-pc-linux-gnu/gcc -D_GNU_SOURCE  -std=gnu99 -Wall -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition
-Wextra -Wwrite-strings -O2 -g -g -O2   -MT unix.lo -MD -MP -MF ".deps/unix.Tpo" -c -o unix.lo `test -f 'io/unix.c' || echo
'../.././libgfortran/'`io/unix.c; \
        then mv -f ".deps/unix.Tpo" ".deps/unix.Plo"; else rm -f ".deps/unix.Tpo"; exit 1; fi
libtool: compile:  /home/jorma/gnu/gcc-4.3.4/host-i686-pc-linux-gnu/gcc/xgcc
-B/home/jorma/gnu/gcc-4.3.4/host-i686-pc-linux-gnu/gcc/ -B/usr/local/i686-pc-linux-gnu/bin/ -B/usr/local/i686-pc-linux-gnu/lib/
-isystem /usr/local/i686-pc-linux-gnu/include -isystem /usr/local/i686-pc-linux-gnu/sys-include -DHAVE_CONFIG_H -I.
-I../.././libgfortran -I. -iquote../.././libgfortran/io -I../.././libgfortran/../gcc -I../.././libgfortran/../gcc/config
-I../../host-i686-pc-linux-gnu/gcc -D_GNU_SOURCE -std=gnu99 -Wall -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition
-Wextra -Wwrite-strings -O2 -g -g -O2 -MT unix.lo -MD -MP -MF .deps/unix.Tpo -c ../.././libgfortran/io/unix.c  -fPIC -DPIC -o
.libs/unix.o
/tmp/ccP6mJ2D.s: Assembler messages:
/tmp/ccP6mJ2D.s:6410: Error: symbol `fstatat64' is already defined
/tmp/ccP6mJ2D.s:6447: Error: symbol `fstat64' is already defined
/tmp/ccP6mJ2D.s:7262: Error: symbol `lstat64' is already defined
/tmp/ccP6mJ2D.s:7295: Error: symbol `stat64' is already defined
make[3]: *** [unix.lo] Virhe 1
make[3]: Poistutaan hakemistosta "/home/jorma/gnu/gcc-4.3.4/i686-pc-linux-gnu/libgfortran"
make[2]: *** [all] Virhe 2
make[2]: Poistutaan hakemistosta "/home/jorma/gnu/gcc-4.3.4/i686-pc-linux-gnu/libgfortran"
make[1]: *** [all-target-libgfortran] Virhe 2
make[1]: Poistutaan hakemistosta "/home/jorma/gnu/gcc-4.3.4"
make: *** [all] Virhe 2

In text above "Poistutaan" means "Exiting" or "Aborting" and "Virhe" means "Error".

After the error message above I thought that I can anyway to install other parts of gcc package and made "make install" with success. But there is anyway some bug with the fortran part of the package.

uname -a gives the following text "2.6.18.2-34-default #1 SMP Mon Nov 27 11:46:27 UTC 2006 i686 i686 i386 GNU/Linux"