My children's choir is finishing up a video for Minecraft and I have run into a problem. A bit in the video has friendly mobs traveling in minecarts. I dug a 1 block deep pit near the gate to my stable. The animals fall in the carts but when I release the carts down the track the mobs turn invisible. You can hear them oinking or mooing but you can't see them. It kind of defeats the point of the bit for the video. Sometimes they appear to be out of the cart and stand on the track like the cow in an old railroad ghost story. You can't interact with them and can travel right through them. Farther down the track they are still invisible in the cart. If I quit and restart the game they become visible. Is this a bug that should be reported or is there a setting for invisible mobs that I haven't found? running version 1.3.2 and Mac OS 10.6.8. Someone suggested I go back to an earlier version but I'm afraid of what that would do to the rest of my video prep. Any suggestions?