When people come on the Snapshot server and try to tame a horse, it kicks them for End of stream in the player.dat files. It can only be fixed by deleting the player. I understand its 1.6 Alfa, but I wanted to address this early on.
Environment
Server - Ubuntu 12.10
Clients - Mac OS X, Windows 7, Windows 8
Server Side Java - JDK 7
Client - 6 and 7
Duplicate of MC-13628, please use the search function to see if your bug has already been submitted. Currently over 54% of tickets are being closed as duplicate.