Compilation error

Hi, I'm novice with postgreSQL and I want to install it. I have
a Sun machine with SunOS 4.1.3.

While I'm compiling, it shows the next error message:

gmake[2]: Entering directory
`/usr/share/src/pgsql/postgresql-6.3.2/src/backend/parser'
/bin/yacc -d gram.y

fatal error: more than 600 rules, line 3318
gmake[2]: *** [parse.h] Error 1
gmake[2]: Leaving directory
`/usr/share/src/pgsql/postgresql-6.3.2/src/backend/parser'
gmake[1]: *** [parser.dir] Error 2
gmake[1]: Leaving directory
`/usr/share/src/pgsql/postgresql-6.3.2/src/backend'
gmake: *** [all] Error 2

What is the problem?
Thanks in advance.

Ricardo Valdivia P.
revaldiv(at)ing(dot)puc(dot)cl