I'm with you; I've already experienced various spooky things with desktop applications on top of Dropbox (like the excellent Papers2 by mekentosj) because of file conflicts and latency. And that's not Papers2's fault, since it would have to be redesigned to be tolerant of such things. But it goes a long way toward showing that Dropbox is not a syncing FS that can put any local application data in the cloud. In particular, Dropbox is bad for typical database use patterns (simultaneous writes, transactions) and the versioning and locking are not tunable.