Bug report: Wrong version in pg_config

Hi,

I'm using postgresql 8.3 in my Ubuntu 8.04 dekstop computer. I have tried to
install postgresql 8.4 for some testing, and removed it afterwards
using *apt-get
purge*.
There are currently no 8.4 packages installed:

*$ dpkg --get-selections | grep postgresql*
postgresql-8.3 install
postgresql-8.3-postgis install
postgresql-client-8.3 install
postgresql-client-common install
postgresql-common install
postgresql-contrib-8.3 install
postgresql-doc-8.3 install
postgresql-plpython-8.3 install
postgresql-server-dev-8.3 install

But still, pg_config remains with the removed version, after postresql
restart and even total reboot:

*$ pg_config*
BINDIR = /usr/lib/postgresql/8.4/bin
DOCDIR = /usr/share/doc/postgresql
HTMLDIR = /usr/share/doc/postgresql
INCLUDEDIR = /usr/include/postgresql
PKGINCLUDEDIR = /usr/include/postgresql
INCLUDEDIR-SERVER = /usr/include/postgresql/8.4/server
LIBDIR = /usr/lib
PKGLIBDIR = /usr/lib/postgresql/8.4/lib
LOCALEDIR = /usr/share/locale
MANDIR = /usr/share/postgresql/8.4/man
SHAREDIR = /usr/share/postgresql/8.4
SYSCONFDIR = /etc/postgresql-common
PGXS = /usr/lib/postgresql/8.4/lib/pgxs/src/makefiles/pgxs.mk
CONFIGURE = '--build=x86_64-linux-gnu' '--prefix=/usr'
'--includedir=/usr/include' '--mandir=/usr/share/man'
'--infodir=/usr/share/info' '--sysconfdir=/etc' '--localstatedir=/var'
'--libexecdir=/usr/lib/postgresql-8.4' '--disable-maintainer-mode'
'--disable-dependency-tracking' '--srcdir=.'
'--mandir=/usr/share/postgresql/8.4/man'
'--with-docdir=/usr/share/doc/postgresql-doc-8.4'
'--sysconfdir=/etc/postgresql-common' '--datadir=/usr/share/postgresql/8.4'
'--bindir=/usr/lib/postgresql/8.4/bin'
'--includedir=/usr/include/postgresql/' '--enable-nls'
'--enable-integer-datetimes' '--enable-thread-safety' '--enable-debug'
'--disable-rpath' '--with-tcl' '--with-perl' '--with-python' '--with-pam'
'--with-krb5' '--with-gssapi' '--with-openssl' '--with-libxml'
'--with-libxslt' '--with-ldap' '--with-ossp-uuid' '--with-gnu-ld'
'--with-tclconfig=/usr/lib/tcl8.5' '--with-tkconfig=/usr/lib/tk8.5'
'--with-includes=/usr/include/tcl8.5'
'--with-system-tzdata=/usr/share/zoneinfo' '--with-pgport=5432' 'CFLAGS=-g
-O2 -g -Wall -O2 -fPIC' 'LDFLAGS=-Wl,-Bsymbolic-functions -Wl,--as-needed'
'build_alias=x86_64-linux-gnu' 'CC=cc' 'CPPFLAGS='
CC = cc
CPPFLAGS = -D_GNU_SOURCE -I/usr/include/libxml2 -I/usr/include/tcl8.5
CFLAGS = -g -O2 -g -Wall -O2 -fPIC -Wall -Wmissing-prototypes
-Wpointer-arith -Wdeclaration-after-statement -Wendif-labels
-fno-strict-aliasing -fwrapv -g
CFLAGS_SL = -fpic
LDFLAGS = -Wl,-Bsymbolic-functions -Wl,--as-needed -Wl,--as-needed
LDFLAGS_SL =
LIBS = -lpgport -lxslt -lxml2 -lpam -lssl -lcrypto -lkrb5 -lcom_err
-lgssapi_krb5 -lz -lreadline -lcrypt -ldl -lm

This creates confusion with external software packages trying to use pgxs,
for example.
Any ideas how to solve this?
Thanks,
Adam