Multiple Foreign Keys to same table and field

Is it possible to have multiple Foreign Keys in one table on different
fields related to the same field in one other table?

I create the 'foreignkey1' on 'table1', 'field4' to foreign table
'table2', 'field1' with ON UPDATE and ON DELETE actions set to CASCADE.
No problem, I can update 'field1' in 'table2' and the update cascades
down to 'table1', 'field4'. However, when I add a second 'foreignkey2'
on 'table1', 'field5' to the same foreign table and field 'table2',
'field1', I get an error when updating the 'field1' in 'table2' value
that says 'ERROR: foreignkey1 referential integrity violation - key
referenced from table1 not found in table2'. If I remove the second
foreignkey2, all works well again with foreignkey1.

I'm new to PostgreSQL, or any SQL database for that matter, but I've
worked with relational databases for years where this is not a problem.
I want two fields in table1 to be dependent on one field in table2 and
cascade the updates or deletions as they occur in table2.

--
Robert