Index: src/game/MapInstanced.cpp
===================================================================
--- src/game/MapInstanced.cpp	(revision 5406)
+++ src/game/MapInstanced.cpp	(working copy)
@@ -296,14 +296,13 @@
 
 void MapInstanced::CreateInstance(uint32 InstanceId, Map* &map)
 {
+    Guard guard(*this);
     if (!IsValidInstance(InstanceId))
     {
         // instance is invalid, need to verify map presence
         if (map)
         {
             // map for the instance is present, but the instance itself is no more valid, destroy map
-            Guard guard(*this);
-
             map->Reset();
             m_InstancedMaps.erase(InstanceId);
             delete map;
@@ -315,8 +314,6 @@
     if (!map)
     {
         // map does not exist, create it
-        Guard guard(*this);
-
         map = new Map(GetId(), GetGridExpiry(), InstanceId);
         m_InstancedMaps[InstanceId] = map;
     }

=====================
Fixe for

#8  0x887a1428 in __cxa_throw () from /usr/lib/libstdc++.so.5
No symbol table info available.
#9  0x886e579e in ZThread::MutexImpl<ZThread::fifo_list, ZThread::NullBehavior>::acquire (this=0x1a8fd0c0) at new_alloca
        i = {_M_cur = 0x888e3dd3, _M_first = 0x1ed0d060,
  _M_last = 0xbf4f93f8, _M_node = 0x887e3b3d}
        self = (class ZThread::ThreadImpl *) 0x92faa00
        m = (ZThread::Monitor &) @0x92faa10: {<ZThread::Status> = {
    _pending = 0,
    _mask = 65527}, <ZThread::NonCopyable> = {<No data fields>},
  _lock = {<ZThread::NonCopyable> = {<No data fields>}, _mtx = 0x92fac00},
  _waitCond = 0x9208c80, _waitLock = 0x92fad80, _owner = 0xc802800,
  _waiting = false}
        state = 209725512
        g1 = {<ZThread::LockHolder<ZThread::FastLock>> = {
    _lock = @0x1a8fd0e8,
    _enabled = true}, <ZThread::NonCopyable> = {<No data fields>}, <No data fields>}
        __func__ = "acquire"
#10 0x886e4c12 in ZThread::Mutex::acquire (this=0x17e) at Mutex.cxx:46
No locals.
#11 0x0836ce33 in MapInstanced::CreateInstance (this=0x1ecfd000,
    InstanceId=4683, map=@0xbf4f9534) at ThreadingModel.h:43
        guard = {i_lock = {i_mutex = @0x1ecfd018}}
#12 0x0836d5e0 in MapInstanced::GetInstance (this=0x1ecfd000, obj=0x206ef000)
    at Object.h:138
        InstanceId = 4683
        instantiator = (class Player *) 0x0
        map = (class Map *) 0x0
        instantiator_id = 152853376
        instantiator_online = 136
        instantiator_bound = 115
#13 0x0818432e in MapManager::GetMap (this=0x92f2c00, id=230, obj=0x206ef000)
    at Map.h:210
        m = (class Map *) 0x0
#14 0x081a18e6 in WorldObject::GetMap (this=0x17e) at Object.h:305