ERROR: could not open relation with OID 909391158

Hackers,

I have been loading 200+ million call records into a new Postgresql 8.1.4 install. Everything has been going great
until a couple of minutes ago. After the process loads a single file (300k to 500k records), it summaries the data into
a summary table. I have been getting the following error message

ERROR: could not open relation with OID 909391158

I don't have any relations with an OID of 909391158, I checked this is the following query

select * from pg_class where oid = 909391158;

I don't know where to go from here. What i have don't to move on is rename the summary table to summary_old and created
a new (empty) one for now. The process is happy with this.

I have search the logs and there are NO hardware related errors. I am running a vacuum full verbose on the summary_old
table now to see if any errors popup.

Any ideas?

Thanks
Jim

select version() returns:
PostgreSQL 8.1.4 on x86_64-unknown-linux-gnu, compiled by GCC gcc (GCC) 4.1.2 20060613 (prerelease) (Debian 4.1.1-5)