Items don't render if they are summoned while dead.

What I expected to happen was...:
When I would summon an item while dead using the /summon Item ~ ~1 ~ command in a command block, that the item would render after you respawn.

What actually happened was...:
The item did not render, but it did exist. (/execute @e[type=Item] ~ ~ ~ say Hi! works and you can pick up the "invisible" item)

Steps to reproduce:
1. Put a command block down with this command:
/kill @p
2. Put a repeater coming out of the command block with the maximum delay.
3. Put a command block after the repeater with this command:
/summon Item ~ ~1 ~
4. Put a button on the first command block and press it.
5. Notice that when you respawn (wait about three seconds before respawning) you can't see the item above the second command block. You still can pick it up though. After you disconnect and connect you can see the item.

Note: This bug only works in multiplayer (vanilla Minecraft server). I haven't tested this with two persons online.