Unable to drop a table due to seemingly non-existent dependencies

Hi,

I have a situation where trying to drop a table results in:

#drop table cdrimporterror_old;
NOTICE: default for table cdrimporterror column cdrimporterrorid
depends on sequence cdrimporterror_cdrimporterrorid_seq
ERROR: cannot drop table cdrimporterror_old because other objects depend on it
HINT: Use DROP ... CASCADE to drop the dependent objects too.

Now as you can probably imply from the name if this table, this table
has been renamed from cdrimporterror to cdrimporterorr_old and I have
(or at least thought I had) removed it's dependency on the sequence by
changing the tables column type (from bigserial to bingint) and
removing the default value. In fact this table no longer has any
constraints or indexes either.

Where would I look to find what was causing Postgres to still be
seeing the sequence as a dependant?

Postgres version is PostgreSQL 8.3.5 on x86_64-unknown-linux-gnu,
compiled by GCC gcc (GCC) 4.1.2 20071124 (Red Hat 4.1.2-42)

Thanks,

David.