Problems with pgcrypto and special characters

Hello!

To get straight to the point, here's my problem:

mypgdb=# select bytea2text(decrypt(encrypt('Tübingen'::bytea, 'mypassphrase'::bytea,'bf'::text),'mypassphrase'::bytea,'bf'::text)) as foo;
foo
-----------------
T\303\274bingen
(1 row)

I have compiled and installed pg_crypto and I'am using the following function as workaround for a bytea-to-text-cast:

create or replace function bytea2text(bytea) returns text as '
begin
return $1;
end;
' language plpgsql;

The cluster was initialized with locale de_DE.UTF-8, pg_controldata confirms:
LC_COLLATE: de_DE.UTF-8
LC_CTYPE: de_DE.UTF-8

Database version is PostgreSQL 8.0.1 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.2

I think I'm missing something very obvious here, so please give me a hint: How can I use pgcrypto to encrypt and decrypt text which contains UTF-8 special characters like german umlauts? I think that this simple bytea2text-function probably needs a replacement, but I haven't got the faintest clue about how to actually retrieve the original input after encryption. Any help would be tremendously appreciated :)

Thanks in advance!

Kind regards

Markus