SQL & PL/SQL

Hi.

I'm having this weird problem in 11.2.0.3

I cant select the dictionary view USER_TAB_COMMENT from a user, but can from others.
If I try to describe it I get ORA-00942 and ORA-04043 messages.

Here is my attempt. I create a comment on a table, try to desc or select the dictionary view. Then connect with SYS, and select the comment in the 'dba' view to check if the comment has been created:

SQL> conn RODOLFO
Introduzca la contraseña:
Conectado.
SQL> show user
USER es "RODOLFO"
SQL> comment on table DOCUMENTILLOS is 'This is a comment';

Comentario creado.

SQL> select table_name, comments from user_tab_comments;
select table_name, comments from user_tab_comments
                                 *
ERROR en línea 1:
ORA-00942: la tabla o vista no existe

SQL> desc user_tab_comments;
ERROR:
ORA-04043: el objeto "SYS"."DBA_TAB_COMMENTS" no existe


SQL> desc all_tab_comments;
ERROR:
ORA-04043: el objeto "SYS"."DBA_TAB_COMMENTS" no existe


SQL> conn / as sysdba
Conectado.
SQL> show user
USER es "SYS"
SQL> select owner, table_name, comments from dba_tab_comments
  2  where owner = 'RODOLFO' and table_name = 'DOCUMENTILLOS'
  3  ;

OWNER                          TABLE_NAME
------------------------------ ------------------------------
COMMENTS
--------------------------------------------------------------------------------
RODOLFO                       DOCUMENTILLOS
This is a comment


SQL>

From other users, I don't have this problem

SQL> conn MANOLO
Introduzca la contraseña:
Conectado.
SQL> show user
USER es "MANOLO"
SQL> comment on table DOCS is 'This is a comment';

Comentario creado.

SQL> select table_name, comments from user_tab_comments where table_name = 'DOCS';

TABLE_NAME
------------------------------
COMMENTS
--------------------------------------------------------------------------------
DOCS
This is a comment

Any clues why this is happening?

Regards.