I had the same listing - probably a bug in the permissions repair, or the way ARD is installed. Feel free to report it as a 'bug' if you like. I expect, like older permissions 'problems', it will turn out to be a cosmetic bug, and not affecting operation in any way. Could be fixed in 10.5.1 - as many users wait for that first 'bug-fix' update before installing a major OS update.
I'm sure Apple is deluged with a variety of items that show up after any major upgrade.