bad packet id 4,5,71

I know that this error is fairly common and i've even had this before, but i forgot the solution, right after that error, i started taking a log of errors and solutions, but i didn't record that, so if someone could post the solution to it, that would be amazing, thanks. oh, and heres the error:

Code:

[Lnet.minecraft.server.Statistic;@a3d4cf
146 recipes
[Lnet.minecraft.server.Statistic;@a3d4cf
16 achievements
14:57:12 [INFO] Starting minecraft server version Beta 1.5_02
14:57:12 [INFO] Loading properties
14:57:12 [INFO] Starting Minecraft server on *:25565
14:57:12 [INFO] This server is running Craftbukkit version git-Bukkit-0.0.0-729-
g5ee3f0f-b766jnks (MC: 1.5_02)
14:57:12 [INFO] Preparing level "world"
14:57:12 [INFO] Preparing start region
14:57:13 [INFO] [ChopTree] Permissions not detected, defaulting to ops.
14:57:13 [INFO] ChopTree 1.21 enabled!
14:57:13 [INFO] Permission system not detected, defaulting to OP
14:57:13 [INFO] [EasyFlight] version [0.3] is Enabled.
14:57:13 [INFO] [EasyTP] Enabled.
14:57:13 [INFO] [EasyTP] Permissions not running, all OPs will be able to use Ea
syTP.
14:57:13 [INFO] Loaded Essentials build 2.2.18 by Zenexer, ementalo, Aelux, Bret
tflan, KimKandor, snowleo, ceulemans and Xeology
14:57:13 [INFO] Loaded EssentialsChat build 2.2.18 by Zenexer, ementalo, Aelux,
Brettflan, KimKandor, snowleo, ceulemans and Xeology
14:57:13 [INFO] Loaded EssentialsGeoIP build 2.2.18 by Zenexer, ementalo, Aelux,
 Brettflan, KimKandor, snowleo, ceulemans and Xeology
14:57:13 [INFO] This product includes GeoLite data created by MaxMind, available
 from http://www.maxmind.com/.
14:57:13 [INFO] Loaded EssentialsProtect build 2.2.18 by Zenexer, ementalo, Aelu
x, Brettflan, KimKandor, snowleo, ceulemans and Xeology
14:57:13 [INFO] Loaded EssentialsSpawn build 2.2.18 by Zenexer, ementalo, Aelux,
 Brettflan, KimKandor, snowleo, ceulemans and Xeology
14:57:13 [INFO] MoveCraft 0.6.8 Final Beta plugin enabled
14:57:13 [INFO] NetherPlugin version 1.2 is enabled without permissions!
14:57:14 [INFO] [RaveBlox] Permissions not enabled.
14:57:14 [INFO] [RaveBlox] Loaded 0 blocks.
14:57:14 [INFO] RaveBlox 1.3a enabled
14:57:14 [INFO] Permission system not detected, defaulting to OP
14:57:14 [INFO] Recoil version 1.1 has been enabled.
14:57:14 [INFO] SearchIds version 2.3 is enabled!.
14:57:14 [INFO] SearchIds: Updating data from https://github.com/mrapple/SearchI
ds/raw/master/search-ids-data.xml...
14:57:15 [INFO] SearchIds: Update complete!
14:57:15 [INFO] Superpickaxe v0.1 by DiddiZ enabled
14:57:15 [INFO] WorldEdit 4.4 enabled.
14:57:15 [INFO] WorldEdit: No known permissions plugin detected. Using configura
tion file for permissions.
14:57:15 [INFO] [xWarp]: 9 warps loaded
14:57:15 [INFO] [xWarp]: No permissions system found until here. A permissions p
lugin will be maybe activated later.
14:57:15 [INFO] [xWarp]: Linked with economy system: Essentials v2.2.18
14:57:15 [INFO] [xWarp]: xWarp 2.11.1 enabled
14:57:15 [INFO] Done (0.299s)! For help, type "help" or "?"
14:57:34 [INFO] noahwhygodwhy [/74.192.25.11:62038] logged in with entity id 15
14:57:34 [WARNING] Missing a prefix or suffix for default
14:57:43 [INFO] º9[PLAYER_COMMAND] noahwhygodwhy: /time day
14:58:29 [INFO] º9[PLAYER_COMMAND] noahwhygodwhy: /i sign
14:58:42 [INFO] º9[PLAYER_COMMAND] noahwhygodwhy: /i signm
14:58:45 [INFO] º9[PLAYER_COMMAND] noahwhygodwhy: /i sign
14:58:54 [SEVERE] java.io.IOException: Bad packet id 71
14:58:54 [SEVERE]       at net.minecraft.server.Packet.a(Packet.java:78)
14:58:54 [SEVERE]       at net.minecraft.server.NetworkManager.f(NetworkManager.
java:128)
14:58:54 [SEVERE]       at net.minecraft.server.NetworkManager.c(NetworkManager.
java:227)
14:58:54 [SEVERE]       at net.minecraft.server.NetworkReaderThread.run(SourceFi
le:69)
14:58:54 [INFO] /216.245.196.122:2524 lost connection
14:59:17 [SEVERE] java.io.IOException: Bad packet id 71
14:59:17 [SEVERE]       at net.minecraft.server.Packet.a(Packet.java:78)
14:59:17 [SEVERE]       at net.minecraft.server.NetworkManager.f(NetworkManager.
java:128)
14:59:17 [SEVERE]       at net.minecraft.server.NetworkManager.c(NetworkManager.
java:227)
14:59:17 [SEVERE]       at net.minecraft.server.NetworkReaderThread.run(SourceFi
le:69)
14:59:17 [INFO] /221.192.199.46:1669 lost connection
14:59:26 [SEVERE] java.io.IOException: Bad packet id 71
14:59:26 [SEVERE]       at net.minecraft.server.Packet.a(Packet.java:78)
14:59:26 [SEVERE]       at net.minecraft.server.NetworkManager.f(NetworkManager.
java:128)
14:59:26 [SEVERE]       at net.minecraft.server.NetworkManager.c(NetworkManager.
java:227)
14:59:26 [SEVERE]       at net.minecraft.server.NetworkReaderThread.run(SourceFi
le:69)
14:59:26 [INFO] /216.245.196.122:2604 lost connection
14:59:27 [SEVERE] java.io.IOException: Bad packet id 5
14:59:27 [SEVERE]       at net.minecraft.server.Packet.a(Packet.java:78)
14:59:27 [SEVERE]       at net.minecraft.server.NetworkManager.f(NetworkManager.
java:128)
14:59:27 [SEVERE]       at net.minecraft.server.NetworkManager.c(NetworkManager.
java:227)
14:59:27 [SEVERE]       at net.minecraft.server.NetworkReaderThread.run(SourceFi
le:69)
14:59:27 [INFO] /221.192.199.46:2679 lost connection
>

 

From what I can tell, it happens when someone tries to login but something goes wrong. The next line is always "xx.xx.xx.xx lost connection". Here's mine: