bug in views/aggregates

I'm not sure if this is a reported bug or not. SELECT statements with some
aggregates on certain complex views can give terrible results. An example:

CREATE TABLE master (   id int4 not null,   no int4 check (no >= 0) default 0,   primary key (id, no),   started date
check((not started is null) or (not closed)),   received date,   starter int4 not null,   description text,   closed
booldefault 'f',   date_of_closing timestamp,   closed_by int4);
 

CREATE TABLE detail (   id int4 not null,   no_ int4 not null,   primary key (id, no_, modification, archive),
orderingint4 not null,   object int4 not null,   ordered_by int4,   quantity numeric(14,4) not null,   quality int4 not
nulldefault 1,   archive bool default 'f',   starting int4,   modification int4 not null check (modification >= 0),
foreignkey (id,modification) referencesmaster(id,no)); 
 

CREATE VIEW buggy_view AS
SELECT de.id, de.no_, de.ordering, de.object, 
de.ordered_by, de.quantity, de.quality, ma.no FROM 
detail de, master ma WHERE 
((((ma.no >= de.starting) AND (ma.no < de.modification)) AND de.archive) 
OR ((ma.no >= de.modification) AND (NOT de.archive))) GROUP BY 
de.id, de.no_, de.ordering, de.object,
de.ordered_by, de.quantity, de.quality, ma.no;

INSERT INTO master VALUES (1,0,now(),now(),1,'','f',now(),1);
INSERT INTO detail VALUES (1,1,1,100,1,1000,1,'f',1,0);
INSERT INTO detail VALUES (1,2,2,101,1,2000,1,'f',1,0);

SELECT count(*) FROM buggy_view; -- I can see two rows of result! :-o

I'm using PostgreSQL 7.0.2.
I am interested in workarounds as well.
TIA, Zoltan