Problem with planer

select ats.id, ap.value from akh_test_suit ats
LEFT JOIN akh_properties ap on ap.ID = ats.test_suit_type_id
where ats.ID = 472

id | value
472 | 472
ID -- integer
value -- text

select * from akh_test_suit ats
LEFT JOIN akh_properties ap on ap.ID = ats.test_suit_type_id
where ats.ID = 472 and ap.value::integer = ats.ID

ERROR: invalid input syntax for integer: "--username sergeiz --password sergeiz --non-interactive svn://sergeiz"

akh_properties.values has non numeric values, but those rows do not (MUST NOT) participate in results as showed in first query
Why PG check them?