CASCADING could not open relation with OID

I've seen that some other people have had ERROR could not open relation
with OID ###

The suggested cause was somebody trying to drop a table in the middle of
VACUUM.

In my case, the error seems to be spreading. Initially it affected only
one table in a staging area that would get TRUNCATEd and populated every
night. Now I'm starting to see it in more tables with similar
functionality.

These get populated by scripts that run at night. Some of these are
crashing. You can see a log below.

Has somebody experienced this before? I'm getting worried, could this be
due to a faulty disk?

In the short term, I think I'm just going to recreate the tables from a
backup of the schema. Any suggestions?

Thanks

Jaime

WARNING: terminating connection because of crash of another server
process

DETAIL: The postmaster has commanded this server process to roll back
the current transaction and exit, because another server process exited
abnormally and possibly corrupted shared memory.

HINT: In a moment you should be able to reconnect to the database and
repeat your command.

CONTEXT: writing block 5529 of relation 1663/16390/686426795