My understanding is that the way it is *supposed* to work is that each DB has a default display state - i.e. when you insert a DB named "stuff", it will indeed be named "stuff" - however, if you change the DB "stuff" to a different style, it is actually an anonymous insert referenced back to the original block "stuff".
At this point, that anonymous block "*U1" for example, is unique within the drawing, however, if you copy "stuff" again and change it to the exact state as "*U1", AutoCAD will actually create "*U2" - but if you copy "*U1", already in that particular state, it won't rename, *unless* you change the state of the block. If there is only one instance of "*U1", changing its state should not change its name.