Join with more strict condition shows the record which is not visible without it

[Michal Jaskolski]

The following query shows exactly one record:

SELECT offer.id as offer_id, product.id as product_id
FROM offer, product
WHERE offer.cache_product_type_id = 86
AND product.source = 'abc'
AND offer.title_original = product.title
AND offer.is_connected !=1
AND offer.id = 11664907

The following query does NOT show the record above:

SELECT offer.id as offer_id, product.id as product_id
FROM offer, product
WHERE offer.cache_product_type_id = 86
AND product.source = 'abc'
AND offer.title_original = product.title
AND offer.is_connected !=1
AND offer.id > 11664906
ORDER BY offer.id

How it is possible? We are using MySQL 5.0.27