compile error

The arcive unzip and tar command execute.
next process ./configure
next process make , just error.
wh？ I don't understanding at error.
tell me advice, please.

$ ./configure
$ make
<<<omission>>>
gcc -I../../include -I../../backend   -O2 -Wall -Wmissing-prototypes -I..   -c -o hba.o hba.c
In file included from hba.c:29:
../../backend/port/inet_aton.h:3: conflicting types for `inet_aton'
/usr/include/arpa/inet.h:69: previous declaration of `inet_aton'
gmake[2]: *** [hba.o] Error 1
gmake[2]: Leaving directory `/usr/src/pgsql/postgresql-6.5.2/src/backend/libpq'
gmake[1]: *** [libpq.dir] Error 2
gmake[1]: Leaving directory `/usr/src/pgsql/postgresql-6.5.2/src/backend'
gmake: *** [all] Error 2

My enviroment:
   install Postgres v6.5.2
   operating system RedHat v7.0 Linux v2.2.16-22
   hardware i586 pentium 266MMX

--nara