Minecraft 1.5.2, Minecraft 1.6.1, Minecraft 1.6.2
Windows 7, 64-bit, Java 7 64-bit
Blocks in minecarts with custom offset stops rendering. This is because the minecart is out of the view of the player, but instead they should be seen. This makes them look glitchy, and the reason for using this blocks is for maps, and for decoration (on server spawns maybe).
MC-1058 A dragon head is invisible if the entity wearing it is not in view