SQL state: 42P01

PG 8.2
Red Hat Linux

Hello -

When I execute the following query,
select A.domain_name_dom, A.word_wdl, A.count_ofi, A.total_quality_ofi, A.avg_quality_ofi
  from zzz_brand2domain_step2_bs2 as A join
        (select B.domain_ofi, B.word_ofi, B.count_ofi, B.total_quality_ofi, B.avg_quality_ofi
           from offpagedomainwordintersection_ofi as B
             where B.domain_ofi != A.domain_name_dom
             order by B.total_quality_ofi desc
             limit 1) as C
         on A.word_wdl = B.word_ofi;

I receive this error message
ERROR:  invalid reference to FROM-clause entry for table "a"
LINE 5:              where B.domain_ofi != A.domain_name_dom
                                           ^
HINT:  There is an entry for table "a", but it cannot be referenced from this part of the query.


And when I execute this query
 select domain_name_dom, word_wdl, count_ofi, total_quality_ofi, avg_quality_ofi
  from zzz_brand2domain_step1_bs1 as B join
     (select * from offpagedomainwordintersection_ofi
                     where B.domain_name_dom = domain_ofi
                       and B.word_wdl = word_ofi
                       and total_quality_ofi >= 5900) as A
                on (domain_name_dom = A.domain_ofi
                 and word_wdl = A.word_ofi )
                       limit 10;

I receive this error message
ERROR:  invalid reference to FROM-clause entry for table "b"
LINE 4:                      where B.domain_name_dom = domain_ofi
                                   ^
HINT:  There is an entry for table "b", but it cannot be referenced from this part of the query.

I don't understand why I can't reference the respective tables in the queries.  Any assistance would be greatly appreciated.

Thank you.

David