Jim - The backup log doesn't match timewise with the other logs, but I'll assume they are from multiple attempts of the same thing. It looks like the /public/proval-old object is bad in some way, and needs examination. If that system hasn't had fsck's in a while, it may be time. I'd code an Exclude for it (or change the 'Exclude /public/*' to an Exclude.Dir on /public, for at least performance reasons) and reattempt the backup. And remove the Virtualmountpoint for /, as it is a file system.
Richard Sims