Small bug for snapshot 13w01b

I have a Redstone level on a superflat world. I have built a cart storage system in which i hit a button and redstone sends only certain carts down to the exit. Another button can be pressed to return the cart. However ever since i got the new snapshot, a bug came up where redstone got stuck after one use of my cart storage. Some redstone even "powered" itself without help of any torches or anything. In these photos, i removed the redstone torches in order to show no redstone power source is near.