Renaming tables and their indexes simultaneously

I have a stored procedure that renames a table as part of a partitioning
scheme, then re-creates it.
Up until recently (I'm not sure what changed), renaming the table would
cause the pkey index/constraint, as well as all other indexes, to be
renamed according to the new table name.
However, they now do not rename, and cause collisions when the new table is
created.

I would prefer not having to drop and re-create the primary key index, as
it takes quite a while to drop and re-create an index that large.

How can I cause Postgres to rename the table's attached indexes when I
rename the table, and what might have caused it to stop doing so recently?

We are on Postgres 9.1, but we did not recently upgrade...

Thanks.

--
Moshe Jacobson
Nead Werx, Inc. | Senior Systems Engineer
2323 Cumberland Parkway, Suite 201 | Atlanta, GA 30339
moshe(at)neadwerx(dot)com | www.neadwerx.com