PgAdmin question (maybe off topic)

Dear list,

When using PgAdmin on Windows 7 (64bit), sometimes I can manage indexes,
sometimes cannot.
Example (can manage indexes normally):

Cannot manage indexes at all:

Must be something related to the table - but it is not permission.

The very same user has the right to execute

drop index ix_localidade;

without any error or trouble. The user has "superuser" rights and is
owner of all tables and indexes in this database.

Can you please clarify what I'm doing wrong?

Thanks,

Edson Richter