errors reported in world.exe when someone logs in...

[Slowtech]

Unknown opcode: 0x48f0 size:0
Unknown opcode: 0x4b80 size:0
Unknown opcode: 0x67ff size:0
Unknown opcode: 0x6afc size:0
Unknown opcode: 0x6cf0 size:0
Unknown opcode: 0x6f80 size:0
Unknown opcode: 0x71c0 size:0
Unknown opcode: 0x7480 size:0
Unknown opcode: 0x67ff size:0
Unknown opcode: 0x69ff size:0
Unknown opcode: 0x6cff size:0
Unknown opcode: 0x6eff size:0
Unknown opcode: 0x71f8 size:0
Unknown opcode: 0x73e0 size:0
Unknown opcode: 0x6eff size:0
Unknown opcode: 0x70fc size:0
Unknown opcode: 0x72f0 size:0
Unknown opcode: 0x74c0 size:0
Unknown opcode: 0x7780 size:0
Unknown opcode: 0x79c0 size:0
Unknown opcode: 0x7c80 size:0
Unknown opcode: 0x69ff size:0
Client disconnected
Removing client from ip:*.*.*.* port:1764


Can someone give me some insight? that client is running XP. Dial up account. He can not get into any server, so I had him log into mine and I get spammed with that. I however can log into my server wit hhis info just fine. Some insight would be appreciated.