Missing FROM clause

Hi,

after seeing some mysterious messages about missing from clauses I did
turn on query logging. Unfortunately am I now more confused then before.

Aug 25 09:22:38 balder postgres[25538]: [277-1] LOG: query: SELECT *
FROM LOGIN
Aug 25 09:22:38 balder postgres[25538]: [277-2] where USERNAME='ulrich'
Aug 25 09:22:47 balder postgres[25590]: [277] NOTICE: Adding missing
FROM-clause entry for table "partner"

Please find the definition of my login table below.

Why would pg add the partner table to the query?

TIA

Ulrich

DB1=> \d login
Table "public.login"
Column | Type | Modifiers
---------------+-------------------------+-------------------------------------------
loginid | integer | not null default
nextval('s_login'::text)
username | character varying(64) | not null
password | character varying(16) | not null
email | character varying(128) | not null
accesslevelid | integer | not null
partnerid | integer |
resellerid | integer |
customerid | integer |
roles | character varying(1024) |
realname | character varying(64) | not null
Indexes: login_p01 primary key btree (loginid),
login_u01 unique btree (username)
Foreign Key constraints: login_f01 FOREIGN KEY (accesslevelid)
REFERENCES accesslevel(accesslevelid) ON UPDATE CASCADE ON DELETE RESTRICT,
login_f02 FOREIGN KEY (partnerid) REFERENCES
partner(partnerid) ON UPDATE CASCADE ON DELETE RESTRICT,
login_f03 FOREIGN KEY (resellerid) REFERENCES
reseller(resellerid) ON UPDATE CASCADE ON DELETE RESTRICT,
login_f04 FOREIGN KEY (customerid) REFERENCES
customer(customerid) ON UPDATE CASCADE ON DELETE RESTRICT