ERROR: Could not locate the record for deletion in the database!

(pgAdmin2, 1.1.59)

When I try to delete a record from a table/view data (select the record,
press delete button), this error message is shown:
"Could not locate the record for deletion in the database!"

This is the table definition:
CREATE TABLE "partners" (
  "id" int8 NOT NULL,
  "firstname" text NOT NULL,
  "lastname" text NOT NULL,
  "company" text,
  "username" text NOT NULL,
  "country" text NOT NULL,
  "state" text,
  "hear" text,
  "regdate" timestamp NOT NULL,
  "email" text NOT NULL,
  CONSTRAINT "partners_pkey" PRIMARY KEY ("id")
);

and this is the log (level: debug)
07/11/2001 8:21:10 AM - Counting matching records...
07/11/2001 8:21:10 AM - SQL (desknow): SELECT count(*) AS count FROM
"partners" WHERE "id" = '119706' AND "firstname" = 'Dario' AND "lastname" =
'gva' AND "company" = 'company' AND "username" = 'dtest4' AND "country" =
'country' AND "state" = 'state' AND "hear" = 'hear' AND "regdate" =
'2001-10-20 18:16:01' AND "email" = 'dario@nowhere.com'
07/11/2001 8:21:10 AM - Done - 0.37 Secs.

Looks like it can't find the record (btw, being a primary key there,
wouldn't it be easier to limit the WHERE clause to it?)
Has it anything to do with 'text' type fields?

Regards

Dario Scopesi