After updating to 1.4.2, coming out of the Nether, I was noticing weird events. I wasn't able to break block (like in a bucket server), when picking up an item off the ground, it would still be on the ground but also in my inventory. The big thing was after a creeper exploded, its body would be in the hole it created, like a ghost. I'm not entirely sure if only happens when coming back from the nether, but it is quite an inconvenience.
There was also a zombie that I killed, but the body stayed there still moving.