Are there any pointers as to how to fix corrupted data? Is seems like that might be the problem as I'm seeing a zero-length read in the log file (see my previous email).
> 1) I'm assuming that if I update 7.3.2 to 7.3.15 I can leave the data in place > (that is, without doing a dump/restore) -- is this correct?
Yes--minor releases don't require dump/restore.
> 2) If I up upgrade to 8.x can just copy the data files or do I have to do a > dump/restore? The latter would be hard since pg_dump also fails on this same > table and pg_dump doesn't seem to have an 'ignore table' option.
You would use the 8.x pg_dump in this case (against the 7.3 database), which may or may not help if you have corrupted table data. If that's the problem, it's best to fix the corruption before trying to upgrade.