Automated analyze process fails with custom function, which works perfect as regular user (8.4.2).

Hello,
I found something weird in the logs.
Apparently the automated analyze process has some
problems with custom functions.

Using my regular database user for this db, i get no problems
using the functions which fail for the automated analyze process.
Can this be a search_path problem?

Extract from log:
------------------------------------------
ERROR: function defined(thirdparty.hstore, text) does not exist at
character 9
HINT: No function matches the given name and argument types. You might
need to add explicit type casts.
QUERY: SELECT defined( $1 , $2 )
CONTEXT: PL/pgSQL function "hstorextract" line 2 at IF
automatic analyze of table "blade.directory.tbldirectory_18410"
------------------------------------------

The "defined" function here is the one shipped by the hstore module.
I imported all contrib modules, into a schema called "thirdparty".

The function hstorextract is defined as:
------------------------------------------------------------------
CREATE OR REPLACE FUNCTION "directory"."hstorextract" (
"inp" "thirdparty"."hstore",
"key" text
)
RETURNS text AS
$body$
BEGIN
IF defined(inp, key) THEN
return inp->key;
ELSE
return null;
END IF;
END;
$body$
LANGUAGE 'plpgsql'
IMMUTABLE
CALLED ON NULL INPUT
SECURITY INVOKER
COST 100;
--------------------------------------------------------------------

tbldirecotry_18410 is a child of the tbldirectory parent table, intended
for data partitioning.

-- tbldirectory_18410 relation definition same as tbldirectory
---------------

From here on I post the defintions: Column | Type
-------------------+--------------------------------+----------------------------------
ficlassinstance | bigint | not null
dtregistered | timestamp without time zone | not null default
now()
dtapproved | boolean | not null default true
firelated | integer[] | not null default
'{}'::integer[]
dtproperties | hstore | not null default
''::hstore
fiklass | integer | not null
dttags | hstore | not null default
''::hstore
dtratings | hstore | not null default
''::hstore
dtvisible | boolean | not null default true
dtspoint | spoint |
dtcheckinspoint | spoint |
dtcheckints | timestamp(0) without time zone |
dtcheckinlocation | bigint |

---------------------------------------------------------------------------------------

I have an index on this table which is as follows, (might play a role):

CREATE INDEX "idx_136_v1_7" ON "directory"."tbldirectory_18410"
USING btree (((hstorextract(dtproperties,
'sphericalProvider'::text))::bigint))
WITH (fillfactor = 70)
WHERE defined(dtproperties, 'sphericalProvider'::text);

------------------------------------------------------------------------

Postgresql Version: 8.4.2..

Thanks in advance,
Patric de Waha