All types of Minecart tested.
Get a one-block tall wall and place two rails connected slantedly. Better powered "Powered Rail". Place a block above the slanted one in which situation this will cut the connection of Redstone. The two rails will not be cut. Run a minecart from the lower rail and see it go through the obstuction.
Also occurs on MCPE. See MCPE-6572
Environment
Windows XP/7/8 (Tested)
Java Runtime Environment 7 Update 40/45 (Tested)
That's a nice diagram. This is at least related to MC-8004, if not a duplicate of it.