We have a strange behavior at one of our customer sites as follows.:

Database ver is Oracle 9.0.1 with RAC option.
Server Operating System : Unix True64
Database Characterset : AR8ISO8859P6
Client Operating System : Windows 2000 Server with arabic enabled
I have two oracle homes :-
HOME1:
- Developer 6 home where sql*plus 8.0.5 is installed .
- NLS_LANG = AMERICAN_AMERICA.AR8MSAWIN.
HOME2:
- Oracle 8.1.7 client home where sql*plus 8.1.7 is installed .
- NLS_LANG = AMERICAN_AMERICA.AR8MSAWIN.

I have created some table called TAB1 with one field (fld char(10))
from HOME1 I've executed the following statment in sqlplus:
Insert into TAB1 Values ('xxx') ;
commit;
<>
from HOME1 RUN from sqlplus:
Select * from TAB1;
it retrieves the xxx characters as english ones for ex.: HGK
from HOME2 RUN from sqlplus:
Select * from TAB1;
it retrieves the xxx characters correct arabic characters .

from HOME2 I've executed the following statment in sqlplus:
Insert into TAB1 Values ('yyy') ;
commit;
<>
from HOME1 RUN from sqlplus:
Select * from TAB1;
it retrieves the yyy characters as english ones for ex.: LMN
from HOME2 RUN from sqlplus:
Select * from TAB1;
it retrieves the yyy characters correct arabic characters .

Can anybody give me the reason and solution for this case .