diff --git a/src/game/GridStates.h b/src/game/GridStates.h
index c41853c5b5c..503b9df15ed 100644
--- a/src/game/GridStates.h
+++ b/src/game/GridStates.h
@@ -24,21 +24,7 @@
 class MANGOS_DLL_DECL GridState
 {
     public:
-#ifdef MANGOS_DEBUG
-#define MAGIC_TESTVAL 0xFBE823BA
-        GridState() { i_Magic = MAGIC_TESTVAL; }
-        bool checkMagic()
-        {
-            if(i_Magic != MAGIC_TESTVAL)
-            {
-                sLog.outError("!!! GridState: Magic value gone !!!");
-                return false;
-            }
-            return true;
-        }
-        void setMagic() { i_Magic = MAGIC_TESTVAL; }
-        unsigned int i_Magic;
-#endif
+
         virtual void Update(Map &, NGridType&, GridInfo &, const uint32 &x, const uint32 &y, const uint32 &t_diff) const = 0;
 };
 
@@ -69,4 +55,5 @@ class MANGOS_DLL_DECL RemovalState : public GridState
 
         void Update(Map &, NGridType &, GridInfo &, const uint32 &x, const uint32 &y, const uint32 &t_diff) const;
 };
+
 #endif
diff --git a/src/game/Map.cpp b/src/game/Map.cpp
index 15ff06b3685..bca4cca367f 100644
--- a/src/game/Map.cpp
+++ b/src/game/Map.cpp
@@ -40,8 +40,6 @@
 #include "VMapFactory.h"
 #include "BattleGroundMgr.h"
 
-GridState* si_GridStates[MAX_GRID_STATE];
-
 struct ScriptAction
 {
     uint64 sourceGUID;
@@ -126,22 +124,6 @@ void Map::LoadMapAndVMap(int gx,int gy)
         LoadVMap(gx, gy);                                   // Only load the data for the base map
 }
 
-void Map::InitStateMachine()
-{
-    si_GridStates[GRID_STATE_INVALID] = new InvalidState;
-    si_GridStates[GRID_STATE_ACTIVE] = new ActiveState;
-    si_GridStates[GRID_STATE_IDLE] = new IdleState;
-    si_GridStates[GRID_STATE_REMOVAL] = new RemovalState;
-}
-
-void Map::DeleteStateMachine()
-{
-    delete si_GridStates[GRID_STATE_INVALID];
-    delete si_GridStates[GRID_STATE_ACTIVE];
-    delete si_GridStates[GRID_STATE_IDLE];
-    delete si_GridStates[GRID_STATE_REMOVAL];
-}
-
 Map::Map(uint32 id, time_t expiry, uint32 InstanceId, uint8 SpawnMode, Map* _parent)
   : i_mapEntry (sMapStore.LookupEntry(id)), i_spawnMode(SpawnMode),
   i_id(id), i_InstanceId(InstanceId), m_unloadTimer(0),
@@ -648,7 +630,7 @@ void Map::Update(const uint32 &t_diff)
             GridInfo *info = i->getSource()->getGridInfoRef();
             ++i;                                                // The update might delete the map and we need the next map before the iterator gets invalid
             ASSERT(grid->GetGridState() >= 0 && grid->GetGridState() < MAX_GRID_STATE);
-            si_GridStates[grid->GetGridState()]->Update(*this, *grid, *info, grid->getX(), grid->getY(), t_diff);
+            sMapMgr.UpdateGridState(grid->GetGridState(), *this, *grid, *info, grid->getX(), grid->getY(), t_diff);
         }
     }
 
diff --git a/src/game/Map.h b/src/game/Map.h
index 7607b49da50..5193d2c7b59 100644
--- a/src/game/Map.h
+++ b/src/game/Map.h
@@ -144,9 +144,6 @@ class MANGOS_DLL_SPEC Map : public GridRefManager<NGridType>, public MaNGOS::Obj
         time_t GetGridExpiry(void) const { return i_gridExpiry; }
         uint32 GetId(void) const { return i_id; }
 
-        static void InitStateMachine();
-        static void DeleteStateMachine();
-
         Map const * GetParent() const { return m_parentMap; }
 
         // some calls like isInWater should not use vmaps due to processor power
diff --git a/src/game/MapManager.cpp b/src/game/MapManager.cpp
index 7feb5ece6d7..5f9622d2f0f 100644
--- a/src/game/MapManager.cpp
+++ b/src/game/MapManager.cpp
@@ -34,9 +34,8 @@
 INSTANTIATE_SINGLETON_2(MapManager, CLASS_LOCK);
 INSTANTIATE_CLASS_MUTEX(MapManager, ACE_Thread_Mutex);
 
-extern GridState* si_GridStates[];                          // debugging code, should be deleted some day
-
-MapManager::MapManager() : i_gridCleanUpDelay(sWorld.getConfig(CONFIG_UINT32_INTERVAL_GRIDCLEAN))
+MapManager::MapManager()
+    : i_gridCleanUpDelay(sWorld.getConfig(CONFIG_UINT32_INTERVAL_GRIDCLEAN))
 {
     i_timer.SetInterval(sWorld.getConfig(CONFIG_UINT32_INTERVAL_MAPUPDATE));
 }
@@ -49,57 +48,45 @@ MapManager::~MapManager()
     for(TransportSet::iterator i = m_Transports.begin(); i != m_Transports.end(); ++i)
         delete *i;
 
-    Map::DeleteStateMachine();
+    DeleteStateMachine();
 }
 
 void
 MapManager::Initialize()
 {
-    Map::InitStateMachine();
+    InitStateMachine();
+    InitMaxInstanceId();
+}
 
-    // debugging code, should be deleted some day
-    {
-        for(int i=0;i<MAX_GRID_STATE; i++)
-        {
-            i_GridStates[i] = si_GridStates[i];
-        }
-        i_GridStateErrorCount = 0;
-    }
+void MapManager::InitStateMachine()
+{
+    si_GridStates[GRID_STATE_INVALID] = new InvalidState;
+    si_GridStates[GRID_STATE_ACTIVE] = new ActiveState;
+    si_GridStates[GRID_STATE_IDLE] = new IdleState;
+    si_GridStates[GRID_STATE_REMOVAL] = new RemovalState;
+}
 
-    InitMaxInstanceId();
+void MapManager::DeleteStateMachine()
+{
+    delete si_GridStates[GRID_STATE_INVALID];
+    delete si_GridStates[GRID_STATE_ACTIVE];
+    delete si_GridStates[GRID_STATE_IDLE];
+    delete si_GridStates[GRID_STATE_REMOVAL];
 }
 
-void MapManager::InitializeVisibilityDistanceInfo()
+void MapManager::UpdateGridState(grid_state_t state, Map& map, NGridType& ngrid, GridInfo& ginfo, const uint32 &x, const uint32 &y, const uint32 &t_diff)
 {
-    for(MapMapType::iterator iter=i_maps.begin(); iter != i_maps.end(); ++iter)
-        (*iter).second->InitVisibilityDistance();
+    // TODO: The grid state array itself is static and therefore 100% safe, however, the data
+    // the state classes in it accesses is not, since grids are shared across maps (for example
+    // in instances), so some sort of locking will be necessary later.
+
+    si_GridStates[state]->Update(map, ngrid, ginfo, x, y, t_diff);
 }
 
-// debugging code, should be deleted some day
-void MapManager::checkAndCorrectGridStatesArray()
+void MapManager::InitializeVisibilityDistanceInfo()
 {
-    bool ok = true;
-    for(int i=0;i<MAX_GRID_STATE; i++)
-    {
-        if(i_GridStates[i] != si_GridStates[i])
-        {
-            sLog.outError("MapManager::checkGridStates(), GridState: si_GridStates is currupt !!!");
-            ok = false;
-            si_GridStates[i] = i_GridStates[i];
-        }
-        #ifdef MANGOS_DEBUG
-        // inner class checking only when compiled with debug
-        if(!si_GridStates[i]->checkMagic())
-        {
-            ok = false;
-            si_GridStates[i]->setMagic();
-        }
-        #endif
-    }
-    if(!ok)
-        ++i_GridStateErrorCount;
-    if(i_GridStateErrorCount > 2)
-        ASSERT(false);                                      // force a crash. Too many errors
+    for(MapMapType::iterator iter=i_maps.begin(); iter != i_maps.end(); ++iter)
+        (*iter).second->InitVisibilityDistance();
 }
 
 Map*
@@ -259,10 +246,7 @@ MapManager::Update(uint32 diff)
         return;
 
     for(MapMapType::iterator iter=i_maps.begin(); iter != i_maps.end(); ++iter)
-    {
-        checkAndCorrectGridStatesArray();                   // debugging code, should be deleted some day
         iter->second->Update((uint32)i_timer.GetCurrent());
-    }
 
     for (TransportSet::iterator iter = m_Transports.begin(); iter != m_Transports.end(); ++iter)
         (*iter)->Update(i_timer.GetCurrent());
diff --git a/src/game/MapManager.h b/src/game/MapManager.h
index c07a7c11ad9..c48f821ba79 100644
--- a/src/game/MapManager.h
+++ b/src/game/MapManager.h
@@ -43,6 +43,8 @@ class MANGOS_DLL_DECL MapManager : public MaNGOS::Singleton<MapManager, MaNGOS::
         Map const* CreateBaseMap(uint32 id) const { return const_cast<MapManager*>(this)->_createBaseMap(id); }
         Map* FindMap(uint32 mapid, uint32 instanceId = 0) const;
 
+        void UpdateGridState(grid_state_t state, Map& map, NGridType& ngrid, GridInfo& ginfo, const uint32 &x, const uint32 &y, const uint32 &t_diff);
+
         // only const version for outer users
         void DeleteInstance(uint32 mapid, uint32 instanceId);
 
@@ -130,17 +132,22 @@ class MANGOS_DLL_DECL MapManager : public MaNGOS::Singleton<MapManager, MaNGOS::
         uint32 GetNumPlayersInInstances();
 
     private:
+
         // debugging code, should be deleted some day
-        void checkAndCorrectGridStatesArray();              // just for debugging to find some memory overwrites
-        GridState* i_GridStates[MAX_GRID_STATE];            // shadow entries to the global array in Map.cpp
+        GridState* si_GridStates[MAX_GRID_STATE];
         int i_GridStateErrorCount;
+
     private:
+
         MapManager();
         ~MapManager();
 
         MapManager(const MapManager &);
         MapManager& operator=(const MapManager &);
 
+        void InitStateMachine();
+        void DeleteStateMachine();
+
         Map* _createBaseMap(uint32 id);
         Map* _findMap(uint32 id) const
         {
diff --git a/src/shared/revision_nr.h b/src/shared/revision_nr.h
index f50169e367e..56cc0a89f0e 100644
--- a/src/shared/revision_nr.h
+++ b/src/shared/revision_nr.h
@@ -1,4 +1,4 @@
 #ifndef __REVISION_NR_H__
 #define __REVISION_NR_H__
- #define REVISION_NR "9995"
+ #define REVISION_NR "9996"
 #endif // __REVISION_NR_H__