It's possible that I'm misunderstanding you, but do you recall this...?
SQL Query
SELECT FORUM_ID, FORUM_TITLE, FORUM_ISLAND_INSERT, PORTAL_ID, PORTAL_NAME FROM ubbt_FORUMS, ubbt_PORTAL_BOXES WHERE FORUM_ISLAND_INSERT = PORTAL_ID AND PORTAL_CUSTOM = '1'
Clearly the query can be massively improved upon (it was done hastily), but it does at least indicate the island and the forum with which it is associated.
