A couple of years ago we hired a new network admin to handle Windows servers and some routine Domino stuff, like registering users. He decided to change the name of our mail server from MAIL to Mail, then updated it everywhere he could find it. I never noticed the change, but I did notice we've had weird errors and never could figure out why.
After upgrading to Domino 7.0.2, resource reservations and the Out Of Office agent simply stopped working. Yesterday I finally noticed the name of the server was different on the Server doc than it was in the server's notes.ini, and I changed it back to the all uppercase spelling.
Voila! Reservations started working (some as far back as 2 years ago) and Out of Office agents started processing properly. I think having it "broken" for so long is going to cause some long-term cleanup problems, but it's mostly fixed now.
The moral of this story is twofold: first, only give admins as much access as they need. Second, don't try to rename a server by just changing its title on the Server document.