The feed server decided to go nuts, ate up lots of CPU, and was suspended by the VPS provider. I thought the virtualization software would have just throttled processor time, but apparently not. So after a clean O/S install, the feed is back online.
Just a note on an issue with memory usage, I found the install of MySQL 5.5 kept using about 300MB of memory regardless of buffer settings. Turned out to be the InnoDB module and after disabling it MySQL only used 20MB of memory, quite a difference.
To disable you need to be aware of a bug (http://bugs.mysql.com/bug.php?id=55608) otherwise just adding 'skip-innodb' will cause the service to say it failed to start. Also remove any 'skip-bdb' entries.