PL/SQL problem under Oracle 7.3.2

When I run the following sql under sqlplus or toad (without the into) it works fine but when I run it from a PLSQL proc it does not resolve the column aliases correctly and the references to r.rcost and a.acost get converted to :b1 and :b2 on the last two lines. Is there a work around for this bug without creating a view based on this sql.

select count(*) into loop_count2

        from  (select x.cumulated_id, sum(prebilled_cost) rcost
                    from bose.r_rated_transactions x,
                            (select distinct subscriber_id from
bose.temp_r_rated_transactions_arch) t,
                              (select distinct cumulated_id from
bose.pb_cumulated_archive) p
                              where t.subscriber_id = x.subscriber_id
                             and x.cumulated_id = p.cumulated_id
                             group by x.cumulated_id) r,
         (select x1.cumulated_id, sum(prebilled_cost) acost
                    from bose.r_rated_transactions_arch x1,


                             (select distinct subscriber_id from


bose.temp_r_rated_transactions_arch) t1,


                             (select distinct cumulated_id from


bose.pb_cumulated_archive) p1
                             where t1.subscriber_id = x1.subscriber_id
                             and x1.cumulated_id = p1.cumulated_id
                             group by x1.cumulated_id) a,
                    bose.pb_cumulated_archive p
           where p.cumulated_id = r.cumulated_id(+)
           and   p.cumulated_id = a.cumulated_id(+)
            and   p.total_amount_net <> (NVL(r.rcost,0) + NVL(a.acost,0))
            and   (NVL(r.rcost,0) + NVL(a.acost,0)) > 0