ERROR: attempted to delete invisible tuple

We had a hardware failure last week and had to switch over to our spare.
Unfortunately, at some point we managed to get some data corruption. I've
been going through the database table by table, record by record, trying to
find the problems and fix them.

This one has me stumped. We have one table with about 13 million records in
it. I've identified 82 bad records. When I try to query for the records,
we get the following:

ERROR: missing chunk number 0 for toast value 25692661 in pg_toast_25497233

That's fine. I've run into that in a few other tables and have just been
deleting the offending records. However, in this particular table, when I
try and delete the records, I get the following error message:

ERROR: attempted to delete invisible tuple

I'm at a loss what to do next.

Thanks,
Bryan