Migration from 8i to 9.0.1(very strange error)

Question

Hi All,
I have a really weird problem. I have 3 different 8i databases (8.0.5, 8.1.6, 8.1.7) and all of them work properly. I have an Oracle 9i (9.0.1) database on another server as well. I used Oracle 8i export(exp command line) to export 8i databases and then used Import 8i (imp command line) to import them to 9i database. Without any error & warning it's done. Everything seems ok on 9i database, but when I issue a very simple query in sqlplus as follow:
SELECT
Table1.column1
FROM
Table1
WHERE
(Table1.column1 = '01' or Table1.column1 is null )
It returns 1 row, which is true. But if I change the query as follow:
SELECT
Table1.column1
FROM
Table1
WHERE
(Table1.column1 = '01' or Table1.column1 is null )
AND (1=2 or 1 in nul)
again it returns one row which is wrong because of that false condition (1=2 or 1 in null), It shouldn't return any rows. But if I create a new table as select * from table1, then it works for new table. So conclusion is something happening at the time of importing to 9i. What is that!? I don't have any idea ! (I did this process for all three 8i databases and got the same result)
If anybody has any comments, I would appreciate it.
Thanks,
Arash
P.S. I did everything to fix the problem ( Reinstall Oracle 9i, create a new database from scratch,...)

Answer 1

Thanks for your time. I did all possible way, but still the same problem. I mean
EXP 8... IMP 8
EXP 8... IMP 9
EXP 9... IMP 9
Today I found that, NLS_LANG of two databases are different. Oracle 8i is : WE8ISO8859P1
AND Oracle9i is : WE8MSWIN1252
So I created a new database from scratch with Oracle 8i character set :WE8ISO8859P1 and then use imp9i to import the file. Still the same problem.
Thanks,
Arash