I am not able to put the exclamation point in a password:

demo40@ORCLDEV> create user testtest identified by testtest;

User created.

demo40@ORCLDEV> alter user testtest identified by test!test;
alter user testtest identified by test!test
*
ERROR at line 1:
ORA-00922: missing or invalid option


demo40@ORCLDEV> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod
PL/SQL Release 10.2.0.1.0 - Production
CORE 10.2.0.1.0 Production
TNS for 32-bit Windows: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production

demo40@ORCLDEV>




Any idea why?