Case bug in SQL Constraint

The SQL query below reports an error if the value "uid" is
provided in uppercase ("UID"). The error reported is:

ERROR: CREATE TABLE: column "UID" named in key does not exist

The problem is eliminated if "UID" is made "uid".
Here is the full text of the query:

CREATE TABLE PASSWD (
NAME VARCHAR(32) NOT NULL,
PASSWD VARCHAR(32),
UID INTEGER NOT NULL,
GID INTEGER NOT NULL,
GECOS VARCHAR(80) NOT NULL,
DIR VARCHAR(256) NOT NULL,
SHELL VARCHAR(256) NOT NULL,
CONSTRAINT "PASSWD_PKEY" PRIMARY KEY ("UID")
)

Thanks, Warren.

Other Info:

$ uname -a
FreeBSD hibiscus.ve3wwg.org 4.4-RC FreeBSD 4.4-RC #1: Wed Oct 17
22:46:11 EDT 2001
root(at)hibiscus(dot)ve3wwg(dot)org:/usr/src/sys/compile/hibiscus i386

wwg=# select version();
version
---------------------------------------------------------------------
PostgreSQL 7.2.1 on i386-portbld-freebsd4.6, compiled by GCC 2.95.3
(1 row)

--
Warren W. Gay VE3WWG
http://home.cogeco.ca/~ve3wwg