Chunks stop loading in Minecarts

In both SSP and SMP, chunks stop loading when riding in a Minecart. The same thing happens when riding in boats. The game will freeze (not crash), and the player has to disconnect/reconnect to get the chunks for force-load.

When on foot, the chunks load fine.

I've recorded video here:
https://youtu.be/XuwN36U5sU0

Thanks!