Jim,
I'm sure it's happened before, but I hardly ever see anyone with oil-bath hub problems. The one incident I did see is a guy that pulled into a WalMart parking lot for a tournament we were having - it was a pre-brief for a Wal-Mart BFL if I remember correctly. It's been many years, so I'm not sure on the event, but it would make sense. Anyway, he had hit something with his rim - hard. It dented the rim edge and ripped off the cap, letting all of the oil drip out. Now, that's not really a fault of the system - he would have damaged most anything that day. However, had it been a grease hub he could have simply put a cap on it or kept on rolling, checking it from time to time. As it was, he couldn't do squat. He was asking around, seeing if anyone had anything he could use. If it were ME, I would have simply accepted one of the grease hubs someone offered him. However, he had it in his head that he NEEDED the oil bathed hub, so he turned down several offers. I'm pretty sure the standard greased hub would have got him to where he needed to go, but he wasn't listening.
All the best,
Glenn