Unable to Delete a Row

I am running Postgres v8.0.1 on Win XP Pro. When I try to delete a
record, which I know exists, I simply get 'DELETE 0' as a response.
Please Help!

Here is a little more info:

DELETE FROM CONTACTS WHERE CONTACTID = 853;

Query returned successfully: 0 rows affected, 62 ms execution time.
-- Executing query:
Select * from contacts where contactid = 853;


Total query runtime: 15 ms.
Data retrieval runtime: 16 ms.
1 rows retrieved.

-- Executing query:
EXPLAIN ANALYSE Delete from contacts where contactid = 853;


Total query runtime: 63 ms.
Data retrieval runtime: 0 ms.
3 rows retrieved.

Thanks in advance

kevin crenshaw