recovery

Suddenly, i started getting some weird errors with a table named xx:

db=> drop sequence xx_cod_seq;
ERROR: DeleteTypeTuple: xx_cod_seq type nonexistent
db=> drop table xx;
ERROR: mdopen: couldn't open xx_pkey: No such file or directory

Then, i noticed the file xx_pkey wasnt at the base directory anymore,
so i create a null file and droped the primary key. Now, I get this error
while trying to drop the table :

db=> drop table xx;
ERROR: DeleteTypeTuple: xx type nonexistent

Ï don't know how it happened, but i noticed that this table isnt on pg_type.

Can some help me ???? How do I fix that so i can't drop this table ?
And how did it happen ?

Regards,

Gustavo Henrique Maultasch de Oliveira
gustavoh(at)sysadmin(dot)com(dot)br