Whenever someone logs out of my survival server, and then they log back in, it causes all maps they view to stop updating the cursor and newly discovered areas. The only way to fix it is to restart the user's client and server. Just restarting the server does not fix the issue.

I also tested the issue in a single player survival world I just created under 13w38c, and I have the same issue. If you save an quit the world, then go back into it without quitting minecraft, the maps will not update. Need to quit Minecraft to fix the issue.