Database Software

I have this problem with Oracle Text that ask me for privileges for anything.
I use two instances of Oracle: in the first one it works like a charm, but the same instruction in the second gives me the error. This is the instruction:

CREATE INDEX SEBU_IDX_PREGUNTAS ON TB_BUS_PREGUNTAS(PREGUNTAB)
INDEXTYPE IS CTXSYS.CONTEXT
PARAMETERS ('SYNC (ON COMMIT) LEXER SEBU_lexer WORDLIST SEBU_word_list FILTER CTXSYS.NULL_FILTER DATASTORE SEBU_MCD_Preguntas');

and the error is (kind of translated from spanish):

ORA-29855: it was an error in the execution of ODCIINDEXCREATE
ORA-20000: Oracle text error:
ORA-01031: insuficient privileges
ORA-06512: in "CTXSYS.DRUE", line 160.
ORA-06512: in "CTXSYS.TEXTINDEXMETHODS", line 366.

I've give my user every grant my ignorance in Oracle allows me. I even have the DBA role.

Done this:

GRANT RESOURCE, CONNECT, CTXAPP TO MyUser ;

Also this:

GRANT EXECUTE ON CTXSYS.CTX_CLS TO MyUser ;
GRANT EXECUTE ON CTXSYS.CTX_DDL TO MyUser ;
GRANT EXECUTE ON CTXSYS.CTX_DOC TO MyUser ;
GRANT EXECUTE ON CTXSYS.CTX_OUTPUT TO MyUser ;
GRANT EXECUTE ON CTXSYS.CTX_QUERY TO MyUser ;
GRANT EXECUTE ON CTXSYS.CTX_REPORT TO MyUser ;
GRANT EXECUTE ON CTXSYS.CTX_THES TO MyUser ;
GRANT EXECUTE ON CTXSYS.CTX_ULEXER TO MyUser ;

The creation of the index actually creates the index but does not create the dr$ tables.
Trying to remove the "corrupted" index also generates the privileges error. However, I can remove table, wich I think also removes the index.

By the way, this index works on a column, not on files.

The creation of the preferences/attributes works:

BEGIN
ctx_ddl.create_preference('SEBU_lexer', 'BASIC_LEXER');
ctx_ddl.set_attribute('SEBU_lexer','index_stems', 'SPANISH');
ctx_ddl.set_attribute('SEBU_lexer','index_text','YES');
END;

Any help will very be appreciated.