Server specs: Ubuntu 11.10 Oneiric Quadcore i7 3.4GHz 16gig DDR3 128gig SSD Screen is allocated 14gigs. This happens with different players every so often. When they join the server it lags the server and eventually crashes it. To fix it I can either delete the players .dat file or edit their .dat file and reset their POS. If anyone has heard of this happening or have a fix from player dat file becoming "corrupted" that would be great. Let me know if you need more information I'll be happy to provide anything that will help solve this issue.