Array in nested query

I'm trying to look up the columns in a constraint in pg_catalog (of
PostgreSQL 8.0.x). I can't figure out how to "join" the elements of the
array that lists the 'attnum's of the columns in the table to the 'conkey'
array in the constraint definition (see
http://www.postgresql.org/docs/8.0/static/catalog-pg-constraint.html and
http://www.postgresql.org/docs/8.0/static/catalog-pg-attribute.html ).

The problem is in the last line of this query:

SELECT a.attname AS name

FROM pg_catalog.pg_class t, pg_catalog.pg_attribute a

WHERE t.oid = 3626912

AND a.attrelid = t.oid

AND a.attnum = any (select conkey FROM pg_catalog.pg_constraint WHERE
oid = 3708025)

I have tried all the variations on this syntax that I can think of, after
plowing through all the documentation of arrays I can find in
http://www.postgresql.org/docs/8.0/static/index.html, and none of them work.

Any ideas?

~ TIA

~ Ken