WARNING: psql version 8.4, server version 9.2.

Hello,
I installed Postgres 9.2 on a new server that has Redhat Enterprise Linux 6, which came with Postgres 8.4. I did not want to use the 8.4 and never ran initdb on it. Instead, I installed postgres 9.2 via yum and di the initdb, etc, on 9.2 and have been using only that version. I have the postgres 8.4 service shut down and set to not start up upon reboot. Whenever I log into one of my databases, I always get this warning:

-bash-4.1$ psql testdb
psql (8.4.13, server 9.2.9)
WARNING: psql version 8.4, server version 9.2.
Some psql features might not work.
Type "help" for help.
testdb =#

Inside the database it says it is version 9.2:
testdb =# select version();
version
--------------------------------------------------------------------------------------------------------------
PostgreSQL 9.2.9 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-4), 64-bit
(1 row)

testdb =#

And the version file of the database says it is 9.2:
-bash-4.1$ cat /var/lib/pgsql/9.2/data/PG_VERSION
9.2
-bash-4.1$

So how can my server have psql 8.4, but server 9.2? So far I have not noticed any problems with the databases and queries against them work, but could it become a problem at some time? Do I have to do something to upgrade the psql 8.4 to 9.2?

Thanks for any advice,
Julie