The bug
In Minecraft 1.3.1 and earlier versions, experience orbs floating around a player would fall to the ground when that player left the server. As of Minecraft 1.3.2, this is no longer the case; instead, the orbs remain floating at the position where the player logged off. This change in behavior may not be intentional, as it was not documented in the changelog for Minecraft 1.3.2.
Steps to reproduce
Enter a world with two players, and label them A and B. This can be done either on a dedicated server or by opening a world to LAN.
Have player A observe player B.
Summon many experience orbs around player B. This can be done, for example, through the use of experience bottles.
While the experience orbs are floating around player B, have them leave the server.
Observed behavior
The experience orbs will remain floating at the position where the player they were surrounding logged off.
Expected behavior
The experience orbs would fall to the ground, as was the case in Minecraft 1.3.1 and earlier versions.
I am able to reproduce the reported behavior. It was introduced in Minecraft 1.3.2.
Minecraft 1.3.1
[media]Minecraft 1.3.2
[media]