join table not getting populated habtm

I am also having a similar problem. I'm using Oracle as my database,
and when I try to create a record in my join table, I get an
ActiveRecord::StatementInvalid exception. It appears that the generated
sql is trying to insert a value into an 'id' column. It originally
complained about not finding a sequence, so I created one just to see
what would happen. Unfortunately, my table, being a join table, doesn't
have an id column. It was created using migrations with the
create_table statement option :id => false. That's why I'm getting an
OCIError: ORA-00904: "ID": invalid identifier error.

Does anyone know how to get AR to stop trying to insert an id into my
join table? Is there something more than :id => false in the
migrations?

Thanks,

-Anthony