In previous builds, the DataSet had a property on them that said whether they should clear the DataSet whenever it is Filled by a DataAdapter. It seems to be missing in the latest builds. I actually prefer this because the nature of DataSets (and often overlooked) is that successive DataAdapter.Fill's will allow a DataSet to grow incrementally. New rows will be added, and existing rows will be updated (unless it is dirty, then you would get an exception).
