We came across an issue where Robocopy was thinking that many files on a given server had been modified from the version that was on a different server. Not a big deal, except "changed files" = "files that need to be copied out", and there were a lot of files that would have been copied over slow links to distant servers. The wierd thing - some folks were seeing the problem with Robocopy, and some were not. Finally narrowed it down.. the people who weren't seeing the problem were on an older version...