non consistent? mixed version setup of binaries

Hallo,

using the apt.postgresql.org repo on debian stable, with versions 8.4 to
9.3 installed,
my psql version reports as 9.3
while my pg_dump version reports as 9.1

eg:
ROOT@server:/var/lib/postgresql# psql --version
psql (PostgreSQL) 9.3.0
ROOT@server:/var/lib/postgresql# pg_dump --version
pg_dump (PostgreSQL) 9.1.9
ROOT@server:/var/lib/postgresql# which pg_dump
/usr/bin/pg_dump
ROOT@server:/var/lib/postgresql# ll /usr/bin/pg_dump
lrwxrwxrwx 1 root root 37 sep  9 14:34 /usr/bin/pg_dump
-> ../share/postgresql-common/pg_wrapper
ROOT@server:/var/lib/postgresql# ls /usr/lib/postgresql/9.1/bin/pg_dump
/usr/lib/postgresql/9.1/bin/pg_dump

so a standard pg_dump on a 9.3 database will fail,
while a standard psql command will succeed;
which seems inconsistent

(the workarounc solution is in the case to use the full path to call the
command)

mvg,
Wim