And further research pointed me to this site where the Mozy Backup icons are listed. The orange/yellow icon in your screen capture looks suspiciously identical to the one at this page:
That's it! Thanks, Rick - my company just started using Mozy for backup so that's got to be it. Doesn't solve my 404 issue for some pages in my Help system, but at least we've eliminated that as a potential reason. Appreciate the help.