After a week of frantic emails, DreamHost has found the problem (they forgot to renew my contract) and put all of my subjectverbobject.com websites back online. Thank goodness.
The most startling thing about all of this was how completely accepting my students were of the hassle and delay that going off-line entailed. They had homework to submit. They were freaked out about their grades. But hey, this is Benin, and nothing ever works right. Everyone took it in stride.