Players get randomly kicked, reason : none

My friends friend came on my server and he kept getting randomly kicked by MCbans from the consel. He bought minecraft 2 days ago and does not know anything! So how could he be hacking or flying? This happen to him 6 times in a row. And this has happen to many player on the server. They just kept randomly getting kicked?

help please

Plugins:
Autokick
Buycraft
ChestShop
Courier
CurseBan
Essentails
EssentailsGeoOP
Factions
FoundDiamonds
LagMeter
Lottery
mcbans
mcmmo
Minebackup
MobDisguise
Multiverse-core
multiversentherportals
multiverseportals
nochatplus
nolagg
openinv
player freeze
playtime
PluginMetrics
Ore Obfuscation
Reservations
ShowCaseStandAlone
Slap
STAB(Stop Talking Auto Ban)
vanish
world portal
worldedit
worldgaurd
XavAutoMessager
Server Log Of Someone Getting Kicked:
2012-04-22 21:17:42 [INFO] [MCBans] Console has kicked michaelm55 [You have been kicked!]
2012-04-22 21:17:42 [INFO] [MCBans] michaelm55 has disconnected!
2012-04-22 21:17:44 [INFO] Connection reset
2012-04-22 21:17:44 [SEVERE] java.net.SocketException: Socket closed
2012-04-22 21:17:44 [SEVERE]at java.net.SocketOutputStream.socketWrite(Unknown Source)
2012-04-22 21:17:44 [SEVERE]at java.net.SocketOutputStream.write(Unknown Source)
2012-04-22 21:17:44 [SEVERE]at java.io.BufferedOutputStream.flushBuffer(Unknown Source)
2012-04-22 21:17:44 [SEVERE]at java.io.BufferedOutputStream.flush(Unknown Source)
2012-04-22 21:17:44 [SEVERE]at java.io.DataOutputStream.flush(Unknown Source)
2012-04-22 21:17:44 [SEVERE]at net.minecraft.server.NetworkWriterThread.run(SourceFile:103)
2012-04-22 21:18:07 [INFO] Connection reset
2012-04-22 21:18:07 [INFO] /94.231.109.47:34021 lost
Please help

 

STAB(Stop Talking Auto Ban)?

 

The most common cause of this is not having 'allow-flight=true'. GO to your server.PROPERTIES file, & change it to true.

 

Got a problem like this one too. My server is falling in ruin. I can't solve this problem (It's like problem #22 in my list )

 

Need some help? I'm quite familiar with many plugin (due to my own server).