Some systems were reporting backup errors without any useful details. After a few blank lines, a <timestamp> would appear with the time of the entry. It was fuond that the code that copies directories was hitting an error, but wasn't correctly entering it into the results. The error itself was not the bug, but rather the fact that the error was not correctly reported. For anyone who is curious, the few cases I did see, the trigger was a root owned file in a Maildir folder... in case that's what you're hitting too.