'Player' Has left the game glitch.

When ever a Non-op player leaves the game. This happens "Player has joined the game."
But when the player is op. This happens "Player has left the game."

Could someone please tell me why this is happening and is there a way to fix it?

These are the plugins I have:
Orebfuscator, Troll, GroupManager, PlugMan, SpleefUltimate, mcjobs, Vanilla, Backup, SafeExplosions, Vault, SignLift, Multiverse-Core, ColourFireWorks, RemoteToolkitPlugin, Permissions, ThisLogMustDie, mcMMO, MobDisguise, FoundDiamonds, Lift, SWatchdog, WorldEdit, RealColoredChat, AntiBot, DrugMod, Multiverse-NetherPortals, ColoredSigns, Message of the Day, PermissionsEx, LogBlock, PlayerStatus, WorldGuard, Jail, Level Up, AutoCast, PotionCraft, SimpleWarps, iConomy, PluginList, Lockette, Modifyworld, iChat, LoginMessage, SimpleHat, HyperConomy, Essentials, Multiverse-Portals, Multiverse-SignPortals, dynmap, DynmapWorldGuard, EssentialsChat, EssentialsSpawn, Dynmap-Essentials, EssentialsGeoIP, JSONAPI, LWC, Factions, dynmap-mobs, Dynmap-Factions, VanishNoPacket, iChatPlayerList, GoinRound

 

I'm guessing its one of your plugins. I think that you have to many… If you have some that have to do with player welcoming/status of players look into that/those plugins.