diff --git a/VERSION b/VERSION
index cf605f9c..4763a852 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-Version 2.00.0 (2012-08-15 14:23:38) dev
+Version 2.00.0 (2012-08-15 14:55:51) dev
diff --git a/gluon/cache.py b/gluon/cache.py
index 437e140e..21b85554 100644
--- a/gluon/cache.py
+++ b/gluon/cache.py
@@ -175,6 +175,7 @@ class CacheInRam(CacheAbstract):
         """
 
         dt = time_expire
+        now = time.time()
 
         self.locker.acquire()
         item = self.storage.get(key, None)
@@ -187,14 +188,14 @@ class CacheInRam(CacheAbstract):
 
         if f is None:
             return None
-        if item and (dt is None or item[0] > time.time() - dt):
+        if item and (dt is None or item[0] > now - dt):
             return item[1]
-        elif item and (item[0] < time.time() - dt) and destroyer:
+        elif item and (item[0] < now - dt) and destroyer:
             destroyer(item[1])
         value = f()
 
         self.locker.acquire()
-        self.storage[key] = (time.time(), value)
+        self.storage[key] = (now, value)
         self.storage[CacheAbstract.cache_stats_name]['misses'] += 1
         self.locker.release()
         return value
@@ -345,15 +346,16 @@ class CacheOnDisk(CacheAbstract):
             if storage:
                 storage.close()
 
+        now = time.time()
         if f is None:
             return None
-        if item and (dt is None or item[0] > time.time() - dt):
+        if item and (dt is None or item[0] > now - dt):
             return item[1]
         value = f()
 
         storage = self._open_shelf_with_lock()
         try:
-            storage[key] = (time.time(), value)
+            storage[key] = (now, value)
 
             storage[CacheAbstract.cache_stats_name] = {
                 'hit_total': storage[CacheAbstract.cache_stats_name]['hit_total'],
diff --git a/gluon/contrib/memcache/__init__.py b/gluon/contrib/memcache/__init__.py
index 667691dd..7079e176 100644
--- a/gluon/contrib/memcache/__init__.py
+++ b/gluon/contrib/memcache/__init__.py
@@ -10,21 +10,19 @@ cache.memcache = MemcacheClient(request,[127.0.0.1:11211],debug=true)
 
 import cPickle as pickle
 import thread
+from gluon import current
 
-locker = thread.allocate_lock()
+DEFAULT_TIME_EXPIRE = 300 # seconds (must be the same as cache.ram)
 
 def MemcacheClient(*a, **b):
-    locker.acquire()
-    try:
-        if not hasattr(MemcacheClient, '__mc_instance'):
-            MemcacheClient.__mc_instance = _MemcacheClient(*a, **b)
-    finally:
-        locker.release()
-    return MemcacheClient.__mc_instance
+    if not hasattr(current,'__mc_instance'):
+        current.__memcache_client = MemcacheClientObj(*a, **b)
+    return current.__memecache_client
 
-class _MemcacheClient(Client):
+class MemcacheClientObj(Client):
 
     meta_storage = {}
+    max_time_expire = 24*3600
 
     def __init__(self, request, servers, debug=0, pickleProtocol=0,
                  pickler=pickle.Pickler, unpickler=pickle.Unpickler,
@@ -45,33 +43,44 @@ class _MemcacheClient(Client):
         else:
             self.storage = self.meta_storage[app]
 
-
-    def __call__(self, key, f, time_expire=300):
+    def __call__(self, key, f,
+                 time_expire=DEFAULT_TIME_EXPIRE,
+                 destroyer = None):
         if time_expire == None:
-            time_expire = 10**10
+            time_expire = self.max_time_expire
         # this must be commented because get and set are redefined
         # key = self.__keyFormat__(key)
+        now = time.time() 
         value = None
-        obj = self.get(key)
-        if obj:
-            value = obj
-        elif f is None:
-            if obj: self.delete(key)
-        else:
+        if f is None:
+            self.delete(key)
+        elif time_expire==0:
             value = f()
-            self.set(key, value, time_expire)
+            self.set(key, value, self.max_time_expire)
+            self.set(key+':time()', now, self.max_time_expire)
+        else:
+            value = self.get(key)
+            t0 = self.get(key+':time()')
+            if value and t0:
+                if (t0 < now - dt) and destroyer:
+                    destroyer(value)
+            else:
+                value = f()
+                self.set(key, value, self.max_time_expire)
+                self.set(key+':time()', now, self.max_time_expire)
         return value
 
-    def increment(self, key, value=1, time_expire=300):
+    def increment(self, key, value=1, time_expire=DEFAULT_TIME_EXPIRE):
+        """ time_expire is ignored """
         newKey = self.__keyFormat__(key)
         obj = Client.get(self, newKey)
         if obj:
             return Client.incr(self, newKey, value)
         else:
-            Client.set(self, newKey, value, time_expire)
+            Client.set(self, newKey, value, self.max_time_expire)
             return value
 
-    def set(self, key, value, time_expire=300):
+    def set(self, key, value, time_expire=DEFAULT_TIME_EXPIRE):
         newKey = self.__keyFormat__(key)
         return Client.set(self, newKey, value, time_expire)