Bixdata server doesn't start on Redhat Linux ES4, 64-bit

When I try to start the server, it says:

-bash-3.00$ ./runserver.sh
bin/initdb: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory
cp: cannot create regular file `data/postgresql.conf': No such file or directory
bin/pg_ctl: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory
Waiting for database
bin/createuser: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory
bin/createdb: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory
bin/pg_ctl: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory
bin/pg_ctl: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory
./bixserver: error while loading shared libraries: libfontconfig.so.1: cannot open shared object file: No such file or directory
bin/pg_ctl: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory

However, the 64-bit version of that file is available:

-bash-3.00$ ls -lda /usr/lib64/libz.so.1
lrwxrwxrwx 1 root root 15 Nov 1 11:28 /usr/lib64/libz.so.1 -> libz.so.1.2.1.2
-bash-3.00$ ls -lda /usr/lib64/libz.so.1.2.1.2
-rwxr-xr-x 1 root root 79336 Jul 12 2005 /usr/lib64/libz.so.1.2.1.2

Is there a 64-bit build of the server available?