pistons and sticky pistons don't rotate when in minecarts

using the new minecart functionality where it is able to display any block, a piston and sticky piston will not rotate in a minecart regardless of data value.

Used MCedit and a filter to change the block to piston and then each minecart has a different data value. As you can see on the screenshot they all look the same. I can confirm the filter does work as it works to rotate pumpkins and it also goes through all the data values of mushroom blocks.