SQL & PL/SQL

Hello,
My Oracle version is 9.2.0.8
OS : AIX 5.2 TL 9

I'm querying only one column-one row of the table using TOAD.

##################### BEGIN #####################

Query:
SELECT PRINT_LINE FROM STATEMENT_LINE WHERE STMT_SEQ=5009211

The result:
DA 216091-01 ¿q :56999136 :5960772

##################### END ######################

See ? You should be able to see "strange" character I mentioned. They are "¿q" and ""
I want to know how to translate these things so I can read them clearly without any "strange" characters.

Is it related to NLS_LANGUAGE parameter ?? if so, I also provide that information (perhaps it's useful, I took this information using sqlplus on the server).
################################
SQL> SHO PARAMETER NLS_LANGUAGE

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
nls_language string AMERICAN
SQL>
################################

Could you all please give me advice what should to do ?

Thank you,
Bayu.