>Got it working! :o) *GGGGGGGG* with the following two changes:
>
>SELECT * from table3 as vh
> INNER JOIN (SELECT tw.* from table1 as tw...
>
>which is almost identical and makes no sense to me, but it returns the correct results. Yahoo! Thanks, thanks, thanks!
>

I'm glad you got it work, but that is strange to me because I tested it that way:

DECLARE @Table3 TABLE (vehi_id Int)
DECLARE @Table2 TABLE (inci_id varchar(14), parent_id varchar(14))
DECLARE @Table1 TABLE (veh_id Int, inci_id varchar(14), canccode varchar(20))


SELECT * from @table3 as vh
 inner join  (SELECT tw.veh_id, qry1.* FROM @table1 tw
                     INNER JOIN (SELECT table2.* FROM @table2 table2
                                        WHERE  table2.inci_id = '07000244      '
                                            or table2.inci_id = '2007093878    '
                                            or table2.parent_id = '07000244      '
                                            or (LEN(table2.parent_id)>0 AND table2.parent_id = '2007093878    ')) qry1
                     ON tw.inci_id = qry1.inci_id WHERE canccode='    ') qry2
on vh.vehi_id = qry2.veh_id

and no error happens.
(of course no result also, but the there should be errors if something is wrong.