SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle8 Enterprise Edition Release 8.0.5.0.0 - Production
PL/SQL Release 8.0.5.0.0 - Production
CORE Version 4.0.5.0.0 - Production
TNS for 32-bit Windows: Version 8.0.5.0.0 - Production
NLSRTL Version 3.3.2.0.0 - Production

SQL> select to_number('54.12','99.99') from dual;

TO_NUMBER('54.12','99.99')
--------------------------
54.12

SQL> c/54.12/,
1* select to_number(',','99.99') from dual
SQL> /

TO_NUMBER(',','99.99')
----------------------
4.12

If its a bug , i couldn't find anything in metalink?
any idea about the bug number???

Thanks
Santosh